The ThomisidÆ are generally flat, short, and widened behind, and have a sidewise gait and crab-like appearance. The first and second legs are often much larger than the third and fourth, and all the legs extend sidewise from the thorax and not forward and backward, as they do in the DrassidÆ (pp. 1-21). The feet have two claws and a thick brush of hairs. They are generally smooth or covered with very short and fine hair, and often have coarser hairs scattered at considerable distances from each other over the back. The eyes are small and in two slightly curved rows, the upper one longest and often much longer than the front row. The mandibles are small and narrowed toward the end. The maxillÆ are narrow at the end and slant inward. Most of the species belong to the three following genera:

Xysticus (p. 30) is flat, with short legs, and marked with gray and brown, like bark and stones.

Misumena (p. 25) is white or brightly colored. The first and second legs are much longer than the third and fourth, and there is great difference between the sexes, the females being large and light colored, while the males are small, and yellow or green, with red and brown markings.

Philodromus (p. 35) is generally small, with long slender legs, the second pair longest. The colors are generally light gray and brown, sometimes with iridescent scales.

Besides the larger genera are several other spiders belonging to this family. Tmarus caudatus (p. 38) resembles Philodromus in color and outline, but has besides the caudate abdomen a very different head and thorax, and the hind legs much shorter than the first and second. Ebo latithorax (p. 38) is a small Philodromus, with a wide body and exaggerated second legs. Thanatus lycosoides (p. 40) is like a stout Philodromus, with rough hairs and markings, resembling some LycosidÆ. Tibellus duttonii (p. 39) is a long straw-colored spider, resembling Philodromus in its feet and head, but having a long slender abdomen, with two black spots.

THE GENUS MISUMENA

The Misumenas are the most conspicuous spiders of their family, and are among the few that are popularly noticed. They grow to a large size and are white or brightly colored, and live in open places on flowers. The males and females differ widely. The males mature early and remain small, and are marked with a variety of colors in spots and bands, while the females grow several times as large, lose in great part their markings, and become white or yellow. In both sexes the two front pairs of legs are much longer than the two hinder pairs, and often differently colored. In the young the colors are variable and there is less difference between the sexes. The Misumenas live on plants, among the flowers, especially on large flat clusters, like those of carrot and thoroughwort. They stand among the flowers, holding by the hind legs, with the front legs extended or bent in stiff and awkward positions, and wait for insects to alight on the flowers within their reach. Whether spiders prefer flowers colored like themselves is an unsettled question; at any rate, Misumenas of all colors and both sexes have been found on white flowers. Occasionally individuals are found on flowers of exactly the same color as themselves; for example, deep yellow M. aleatoria on the wild indigo, Baptisia tinctoria, and the reddish M. asperata on the flowers of sorrel, Rumex acetosella. The adult females of vatia and aleatoria are easily mistaken for each other. Both vary in color from white to deep yellow, and grow to a large size, but they can be distinguished by the difference in the shape of the head. Asperata is perhaps the most common species. The female seldom grows as large as the others, and does not lose entirely the red markings of the abdomen and legs. The scattered stiff hairs also distinguish it from the others. The males of the different species are distinct enough one from the other, though they differ widely from the females. The shape of the head and the markings around the eyes are much the same in both sexes, and by these males and females of the same species may be recognized.

Misumena vatia is the largest species and lives all over this country and Europe. It is sometimes half an inch long, and the first legs spread an inch and a half (fig. 77). It is white, with sometimes a crimson spot on each side of the abdomen and another on the front of the head between the upper eyes. The sides of the thorax are a little darkened with yellow or brown, which extends around the head to a distinct opaque white spot under and between the eyes (fig. 76). This white spot widens below over the mandibles and above under the eyes and around the eyes of the upper row. The shape of this mark and the greater height of the head distinguish this species from aleatoria (figs. 79, 80). On the back of the thorax is also a distinct opaque white spot. The first and second legs have usually a light brown mark on the upper side, but this is sometimes absent.

The male (fig. 78) is only a quarter or a third as long as the adult female. The front legs are proportionally longer than in the female, and the abdomen smaller and more pointed behind. The males are strongly marked with reddish brown on a light ground. The thorax is dark at the sides, while the front of the head is white like that of the female.

Misumena aleatoria.—The female of this species grows nearly as large as vatia, and in some places is much more common. It is white or yellow, but does not have the crimson markings at the sides of the abdomen or between the eyes. The head (fig. 79) is rounder than in vatia and much lower in front, and there is a narrow white stripe under the eyes that divides at the sides, one branch passing around over the mandibles and the other close under the eyes. The sides of the cephalothorax are gray or green. The abdomen usually has no markings except a little gray color in the middle, but sometimes it has two rows of dark brown spots (fig. 81), and in such individuals the legs are also marked with brown at the ends of the joints. The males are very small and strikingly colored (fig. 82). The two front pairs of legs are brown, the cephalothorax green, and the abdomen yellow. The shape of the head and the white under the eyes are the same as in the female.

Misumena asperata.—The males and females of this spider are more alike than in vatia and aleatoria. The adult females are always pale and sometimes white, but seldom lose entirely the reddish bands around the legs. Both sexes are covered with short stiff hairs about their length apart all over the upper part of the body and legs. The usual color is pale yellow, with dull red markings. The thorax is reddish at the sides. The abdomen has two red bands or rows of spots on the hinder half, meeting behind. In front are a middle pair of spots and two side bands that spread apart in the middle and meet again at the spinnerets. The tibia and tarsus of the front legs are marked with a narrow red ring at the base and a wider ring near the end of each joint. The female is a quarter of an inch long and the male about half that length. The markings of the male are like those of the female, but the spots are larger and more deeply colored. The male palpi are larger than in the other species.

The male M. spinosa of Georgia resembles asperata, but the legs are much longer and the ends of the palpi smaller.

Synema parvula.—A common species in the South. Length about one-eighth of an inch. The thorax is as wide as long, round and high in the middle. The abdomen is as wide as long, widest across the middle, and a little pointed behind. The third and fourth legs are not more than two-thirds as long as the first and second, and lighter colored. The thorax is orange-colored, a little darker at the sides, and with a dark brown line on the edges over the legs. There are light rings around the eyes. The abdomen is white or light yellow in front, and has a wide black or brown band across the hinder half, not reaching back to the spinnerets, and sometimes partly divided by a notch in front. On the front half of the abdomen are some small dark spots and usually several opaque white marks. On the under side of the abdomen there is a dark band on each side extending back to and partly surrounding the spinnerets. The front legs are orange brown, with the femora darker on the front and rear edges. The other joints are a little darker at the ends. The males are a little smaller and darker in color, but differ little from the females.

THE GENUS XYSTICUS

In these spiders the general appearance is crab-like. The abdomen is not much larger than the thorax, and both are flat and wide. The first and second legs are a third longer than the third and fourth. The colors are usually various shades of brown and gray, in small spots and bands. On the upper side of each leg is usually a light line, with dark lines on each side of it. The gait is often sidewise, the legs kept close to the ground, so that the spider can move in a narrow crack. They live under stones and bark and leaves, and some, like triguttatus, on low plants. The males have longer legs and smaller abdomen and all the dark markings larger and darker than the females. In triguttatus there is great difference between the sexes, but in most species very little, as in limbatus and stomachosus. The head is generally low, and the four middle eyes form a rectangle a little wider than high (fig. 97).

Xysticus stomachosus.—A middle-sized and light-colored species, with gray markings on a light ground, the markings most distinct on the hinder legs and abdomen. The middle of the thorax is lighter than the sides, and there is a small dark spot in the middle and a larger one on each side toward the hinder end (figs. 87, 88). The third and fourth legs have a distinct dark spot at the ends of femur, patella, and tibia. The abdomen is light, with a few small spots at the front end and three pairs of dark transverse bands on the hinder half. The hairs are short and fine. The male has longer legs and is marked in the same way, with the spots on the abdomen larger and extended farther forward.

Xysticus limbatus.—This is one of the largest species, the females reaching a length of a third to half an inch (figs. 89, 90). The thorax is one-eighth of an inch wide and nearly as long. The abdomen is a little wider at the hinder end. The legs are short, the longest about half an inch in length. The whole body is hairy. The color is brown, the markings dark on a light ground, best shown by the figures. The middle of the head and thorax is more fully covered by the dark markings than in other species. There is great variation in the color, and young spiders are usually lighter than adults. Adult males and females in June and July.

Xysticus gulosus.—This is a very distinct species and less variable in markings than limbatus and stomachosus. The color is brown or gray, with indistinct darker markings (figs. 91, 92). The whole body is covered with fine brown spots and has at the hinder end of the thorax and on the legs traces of the same markings that show more distinctly in stomachosus. There are a few transverse dark lines on the hinder half of the abdomen and less distinct longitudinal lines at the sides of the front half.

The male is a fourth smaller than the female, with a smaller abdomen and more slender legs, but the same colors and markings. It is usually found under bark or stones which it closely resembles in color.

Xysticus nervosus.—This is a pale species, the females of which are nearly as large as limbatus. The color is light brownish yellow, with small spots of lighter and darker color scattered all over the body, and there are traces of the markings which are more distinct in other species (figs. 93, 94). On the hinder half of the abdomen are three or four pairs of very indistinct transverse markings. The legs are marked with irregular dark and light spots, without any distinct rings or markings, and the first and second pairs are darker than the others. In the male the first and second legs are twice as long as the third and longer and more slender than in the other species. It lives on fences and under bark.

Xysticus triguttatus.—This is a small and very common spider living on grass and low bushes. The female is about a fifth of an inch long and the male as large but with a smaller abdomen. The difference in the color of the sexes is so great that they may easily be mistaken for different species. The females (fig. 95) are straw-colored, the abdomen almost white, and the thorax and legs brownish yellow. There are three black spots at the back of the thorax and indistinct darker bands at the sides. On the abdomen are two black spots near the front end and three pairs of broken transverse stripes behind. The male (fig. 96) has the femora of the two front legs dark brown, the rest like the female or a little darker. The thorax is dark brown, except in the middle, where it is a little lighter, as in the female. The abdomen of the male is strongly marked with transverse black and white stripes, irregular toward the front end.

Xysticus quadrilineatus.—Quarter of an inch long, with the thorax a tenth of an inch wide and the head unusually wide in front. The color is light yellow, with light brown markings and black spots. The cephalothorax has four narrow brown stripes, one on each side close to the edge and the others running back from the lateral eyes (fig. 98); there are also two fine brown lines sometimes extending from the middle eyes to the dorsal groove, but usually broken in the middle. There is a brown spot just behind the dorsal groove and two others in the middle of the cephalothorax. On the abdomen there are two black spots at the front end, two in the middle and two near the hind end, besides several smaller ones along the sides. There are four light brown lines across the hinder half, each with a white line behind it, and at the sides are oblique brown lines alternating with white. The legs have a distinct light line along the dorsal side and are covered with fine brown spots without any other markings.

Xysticus (Coriarachne) versicolor.—The thorax, abdomen, and legs are all much flattened, the head is low, and the upper and lower eyes nearer together than in the other species. The colors are black and gray in irregular spots on a light ground (figs. 99, 100). On bark or unpainted wood these spiders can hardly be seen. Light individuals have black spots on the legs at the end of each joint and the usual three pairs of dark marks on the abdomen. On the thorax is a white spot in the middle under the front of the abdomen. Around this spot and behind the eyes is black extending in spots along the sides. In dark females and in most males the dark spots are so large that the whole spider is nearly black.

This is a common spider, and a similar species, Coriarachne depressa, is equally common in Europe.

THE GENUS PHILODROMUS

In these spiders there is less difference in length between the front and hind legs than in Misumena or Xysticus. The legs are long and slender, the second pair longest, and the body is small and flat, and the abdomen pointed behind. The colors are brown and gray, and the whole body is often covered with fine flattened hairs that in the males are iridescent. Philodromus vulgaris lives usually on houses and fences, but the other species on plants.

Philodromus vulgaris.—About quarter of an inch long, the legs of the female spreading over an inch and those of the male an inch and a quarter (figs. 101, 102). They often stand with all the legs extended sidewise, flat against a wall or fence which they closely resemble in color. When freshly molted they are covered with fine gray hairs of the color of weathered boards, that obscure most of the markings. Older spiders or those wet with alcohol are covered with small gray spots forming a stripe in the middle of the front of the abdomen and a herringbone pattern on the hinder half. The edges of the back of the abdomen are dark and form a sharp line against the light color of the under surface. The thorax is darker in the middle and at the sides in irregular spots of gray. The legs are spotted and darker toward the ends of the joints. The under side of body and legs is light colored.

Philodromus ornatus.—This is a small species about one-eighth of an inch long. The female is very distinctly marked with dark brown on a white ground (fig. 105). The middle of the thorax is white and the sides brown nearly to the edge. The abdomen is white, with a distinct brown band on each side from the front more than half its length backward. Sometimes there is also an indistinct brownish pattern in the middle, but this is usually absent in adults, and the middle is entirely white. Under the abdomen the lateral brown bands extend backward and meet around the spinnerets. The abdomen is wider than in most species,—nearly as wide as it is long across the hinder half. The male is very differently colored. The legs and thorax are orange brown, darker at the sides of the thorax and toward the ends of the legs. The abdomen is darker brown and strongly iridescent with red and green in a bright light. In alcohol it shows indistinctly the same markings as the female. The legs are longer and the abdomen narrower, as in males of other species.

Philodromus lineatus.—The female of this species is a little larger than ornatus, the brown markings are lighter, and, in life or when freshly killed, purplish in the lighter parts. The markings are less distinct than in ornatus, the brown and white running into each other. The abdomen has a brown band each side, often broken into several spots, and a brown band in the middle extending back half its length, behind which are several lighter marks (figs. 106,107). Between these are several oblique lighter markings and rows of spots. The legs are light gray, darker toward the ends of the joints.

Philodromus pictus.—Female about one-fifth of an inch long, the abdomen nearly twice as long as the thorax, with the widest part across the middle farther forward than in most species (fig. 110). Legs and palpi pale yellow with fine brown spots. Thorax light yellow in the middle and reddish brown at the sides, covered with fine spots. Abdomen dull red at the sides and bright yellow in the middle, with a dark mark in the middle of the front half and two dark marks behind it on the hinder half. The eyes are surrounded by distinct light rings. In some specimens, usually immature, the abdomen has a more distinct yellow and red pattern (fig. 108). The male (fig. 109) has the thorax and legs darker and the abdomen less bright red and yellow than the female, sometimes gray and iridescent.

Ebo latithorax.—In color and general appearance this resembles Philodromus, but is at once distinguished by the length Of the second legs, which are more than twice as long as any of the others (fig. 111). The thorax is wider than long, and the abdomen is wider than in Philodromus. The head is narrow and rounded in front. The front middle eyes are largest and farthest forward. The colors are gray and white, with black spots in the darker parts, as in Philodromus. The length is not much over an eighth of an inch and the length of the longest legs quarter of an inch.

Tmarus caudatus.—This spider is about as large as Philodromus vulgaris and similarly colored, but may be distinguished from it by the height of its abdomen and the short tail or projection over the spinnerets (fig. 113). The thorax is round at the sides and square in front, and the mandibles are inclined forward so that they can be seen from above. The two rows of eyes are farther apart than in Philodromus, and the lateral eyes of both rows are raised on tubercles. Among the eyes are several black spots that may be mistaken for extra eyes, and there are similar spots on the legs, most thickly on the front pairs. On the back of the thorax are radiating white lines. The abdomen is light in front and marked behind with two or three pairs of indistinct transverse lines (fig. 112). On the under side the whole body and legs are pale, without spots except a wide middle band of gray under the abdomen. The third and fourth legs are shorter than the first and second, the difference being greater than in Philodromus and less than in Misumena.

Tibellus duttonii.—This is a very common spider on bushes and grass. The body is slender, from a third to half an inch long, and a tenth of an inch wide (fig. 115). The thorax is an eighth of an inch long, widest across the hinder half and narrowed toward the front, where it is cut off nearly straight over the mandibles. Both rows of eyes are strongly curved (fig. 116). The hinder row is twice as long as the front row and all the eyes larger. The abdomen is straight at the sides and a little pointed behind. The color is light gray or yellow, with a darker gray line in the middle, divided into two toward the eyes. At the sides of the thorax are other longitudinal lines. On the abdomen, one-third its length from the hinder end, is a pair of small round or oval black spots. The legs are light gray, with no markings except a few black hairs.

Thanatus coloradensis or lycosoides.—In color and general appearance this resembles Philodromus, but is not as flat, and the legs are not as long and slender. The general color is light gray, with a distinct wide light stripe in the middle of the thorax, and a dark brown pointed stripe with white edges in the middle of the front half of the abdomen (fig. 117). The head is a little longer and higher than in most ThomisidÆ, and the abdomen is a little longer and not so much widened behind. The eyes are much as in Philodromus, but larger and nearer together. The whole body is hairy, with longer and darker hairs scattered among the short ones. The males differ but little from the females except in having a little longer hairs and darker color. They live on plants and may be mistaken for Philodromus (p. 35) or for Ocyale undata (p. 88).

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