The LinyphiadÆ consist of a great number of species of small spiders living, for the most part, in shady woods, among the lower branches of plants, under leaves, and in caves and cellars. They differ from the TherididÆ generally in having the body more elongated, the legs stouter and with more spines, the mandibles larger and stronger and furnished with teeth around the claw, and the maxillÆ straighter and not inclined inward toward the labium. There are two groups among them,—Linyphia and its allies, which are comparatively large and some of which live in the open woods, with large cobwebs, and Erigone and its allies, which are all very small spiders, living mostly in short grass, dead leaves, and moss. The latter usually have narrower bodies and stouter legs, resembling the DrassidÆ. Their colors are generally plain and dull, and the females are difficult to distinguish from each other, while the males often have peculiar modifications of the head and proportionally very large and complicated palpi. The webs usually have a large flat sheet, supported by threads above and below, under which the spider lives. Some species have the sheet of web curved upward or downward. Linyphia marginata forms a dome-shaped web four or five inches in diameter. THE GENUS LINYPHIAThese spiders vary in size like the species of Theridium, from a quarter of an inch to a tenth of an inch long. In appearance they differ greatly from Theridium; the cephalothorax is Linyphia marginata.—This is one of the most common web spiders in shady woods all through the summer. It is a sixth of an inch long, with slender legs, the longest of which are usually half an inch. The cephalothorax is two-thirds as wide as long, the middle of it brown and the edges light. The abdomen is flat on top and widest and thickest behind, the colors light yellow and purplish brown (fig. 319). In the middle there is a dark stripe, consisting usually of three parts united by a narrow line, and behind this is another dark spot. At the sides are several dark stripes, the front ones lengthwise and the hinder vertical, all connected with the dark color of the under side. The legs are light yellow without markings, and the hairs and spines fine and not easily seen. In the males all the colors are darker and the abdomen narrower, with only a few light marks at the sides. This spider has no nest, but lives all the time in the middle of its web. It matures in June, and the young brood are common in their small webs in August and September. The web of L. marginata (fig. 318) is in the form of a dome four or five inches in diameter, hung between rocks and plants, seldom much concealed by leaves. The threads are fine, and the web so transparent that it easily escapes notice unless the sun shines upon it. The meshes are larger than in L. phrygiana and other flat web-making species. The depth and width of the dome depend somewhat on the shape of the opening Linyphia communis.—A little smaller than marginata, with legs a little shorter. The colors are the same light yellow and purplish brown, but the markings are distinctly different. The cephalothorax is uniform light brownish yellow. The middle stripe of the abdomen extends the whole length of the upper side and connects with several narrow brown stripes that extend down the sides (fig. 323). The abdomen is more regularly oval and less enlarged behind than in marginata, but the upper part extends back farther over the spinnerets. The under side is Linyphia mandibulata.—A little larger than L. communis and marginata, with the head longer and more distinct from the thorax, and the abdomen larger and flattened on the top (figs. 326, 327). The length is about a sixth of an inch. The cephalothorax is dark orange brown, and the legs a lighter shade of the same color. The length of the legs is about as in communis, shorter than marginata and phrygiana. The abdomen is dark brown, often almost black, with several white spots, usually two across the front end and several others around the sides (fig. 326), sometimes forming a complete light stripe around the middle. In the males the abdomen is narrow, and the only markings are usually the two spots on the front end. The cephalothorax of the male is long and narrow; the head is extended forward, and the mandibles inclined backward toward the maxillÆ. The mandibles are more than half as long as the cephalothorax and widened at the ends, with four teeth on the inner corner (fig. 329). On the inner side of the mandibles, near the middle, is a large blunt tooth. The webs are flat and near the ground, on short grass and leaves and across little hollows in the sod (fig. 325). The webs Linyphia coccinea.—About a sixth of an inch long and bright red and orange color. The size and length of legs are about the same as in communis. The legs are light orange, the cephalothorax a deeper shade of the same color, and the abdomen light red. The palpi have the ends black, and the legs are sometimes streaked with black. The hinder middle eyes are Linyphia phrygiana.—This is one of the most common species and lives both in the woods and around houses. It is larger than marginata Linyphia (Stemonyphantes) trilineata.—About a quarter of an inch long, with a large oval abdomen and comparatively short legs. The color is light yellowish gray, the cephalothorax with three dark lines, and the abdomen with three rows of dark spots partly connected in lines. The legs are marked with dark rings on the ends and middle of the joints, more distinctly on the under than on the upper side. The sternum is light in the middle and black around the edge, and the abdomen has irregular black spots at the sides and beneath. The male has longer legs and wider thorax and smaller abdomen. It lives under stones and logs and winters under leaves in the woods. It is common both in this country and Europe. Linyphia (Bathyphantes) nebulosa.—Length a sixth of an inch. Color light brownish yellow, with gray markings (fig. 338). Some are almost white, and others are dark, with the black spots covering a large part of the body. The cephalothorax is dark on the edges and has a dark middle stripe, forked toward the eyes. The abdomen has six or seven pairs of irregular dark spots, more or less connected with a dark middle line. The under side of abdomen and sternum have black spots which, in dark individuals, run together, making these parts entirely black. The legs have dark rings on the ends and Linyphia (Bathyphantes) minuta.—One-eighth of an inch long, a little smaller than nebulosa. The cephalothorax is yellowish brown, darker at the edges, but without any middle line. The dark markings of the abdomen nearly cover it, so that it appears dark gray with light markings instead of Linyphia (Drapetisca) socialis.—This very distinct species is marked with gray and white and is often found on the bark of trees without any web. It is a tenth to an eighth of an inch in length. The cephalothorax is white with black edges, a black spot in front under the eyes, and a black mark in the middle, from which indistinct lines radiate toward the edge. The abdomen is widest just behind the middle (fig. 345). It is white, mottled with gray, and has a Linyphia (Helophora) insignis.—An eighth of an inch long, as long as socialis, but more slender. The cephalothorax and legs are light yellow, and the abdomen gray or white, sometimes without markings and sometimes with gray stripes at the sides and two or three pairs of gray marks across the hinder half (fig. 348). The cephalothorax of the male is twice as wide across the middle as at the head. The legs are without markings. The epigynum (fig. 350) is long and straight, extending backward close to the abdomen for half its length. The tibia Linyphia (Diplostyla) concolor.—About a twelfth of an inch long, a little smaller than nigrina, with long slender legs, and the abdomen slightly pointed toward the spinnerets and not much larger than the cephalothorax. The color is light yellow brown, the abdomen gray without any markings. The epigynum (figs. 352, 353) has a long, slender, flexible process on the outer edge that extends backward to the middle of the abdomen, and under it is another shorter one not easily seen. The tarsus of the male palpus (fig. 351) is longer and more tapering than that of nigrina. Adults of both sexes are common under leaves in winter all over the northern part of the country. Linyphia (Diplostyla) nigrina.—A tenth of an inch long. Cephalothorax and legs light yellow brown. Abdomen dark THE GENUS ERIGONEThe Erigones are all very small spiders, and for this reason few of them will be described. They live, for the most part, near the ground in grass, moss, and dead leaves, with small webs like those of Linyphia, and are seldom seen unless carefully searched for. There is one season of the year, however, when the Erigones appear in immense numbers. This is during the fine weather that comes after the first frosts in Erigone longipalpis and dentigera.—These spiders are a tenth of an inch to a twentieth of an inch long and generally dark brown in color, with the cephalothorax smooth and shining. Erigone autumnalis.—This is one of the few species of Erigone that can be distinctly separated from the others. It lives in the same places and is found with longipalpis in the autumn flights. It is only a twentieth of an inch long, but can be distinguished by its light color and bright yellow head. The palpi of the males have the tibia shorter than the patella and the tooth on the patella turned more forward than in longipalpis, with a longer and sharper point tapering from the base to the tip (fig. 367). Ceratinella lÆtabilis.—This is about the same size as fissiceps,—a sixteenth of an inch long,—but much darker colored, and the males do not have horns or humps on the head. The cephalothorax and sternum are dark brown, and the legs dark orange. The thickened circle on the abdomen (fig. 368) is dark orange brown and the thinner parts gray. In the female the thick circle is usually wanting and the whole abdomen dark gray, with lighter spots around the muscular marks. There are also hardened spots around the stem of the abdomen and under the spinnerets in both sexes. The head is slightly elevated behind the eyes, a little more in the male than in the female. The male palpi (figs. 369, 370) Ceratinella fissiceps.—These little spiders are among the smallest species, measuring only a sixteenth of an inch in length. The cephalothorax and abdomen are short and round, and the abdomen has a round thickened spot on the back, more deeply orange colored than the part around it. The head is black around the eyes, and a black line extends backward half the length of the cephalothorax. The head of the male extends forward over the mandibles, carrying with it the front middle eyes, and above it is a rounded hump with the hind middle eyes. The pairs of lateral eyes are opposite the crease between the humps (figs. 371). The female has at the same point a slight crease across the head and an elevation before and behind it. They are very common on low bushes in summer and under leaves in winter, and are occasionally seen in the autumn flights. Cornicularia directa.—The males and females are of the Ceratinopsis interpres.—Length about a tenth of an inch. Color bright orange, with a little black around the eyes and the spinnerets. In the female the height of the head equals the length of the mandibles, and in males it is greater. The size of the sexes is about the same. The upper middle eyes are a little larger and farther apart than the front middle pair, and between them is a flattened space covered with stiff black hairs, longer in the male than in the female (fig. 377). The male palpi have the femur as thick as the femur of the first leg and the tibia very short and wide, with a little recurved point on the front edge. They live on low bushes in summer and under leaves in winter. |