  THE STEREOSPONDYLOUS AMPHIBIA FROM THE COAL MEASURES OF NORTH AMERICA. DEFINITION OF THE ORDER STEREOSPONDYLIA ZITTEL, 1887. Zittel, Handbuch der Paleontologie, Bd. III, Abth. 1, p. 397, 1887. Large terrestrial vertebrates; largest of the class. Skull equal to one-fourth or one-third of the entire body in at least one species, Metoposaurus diagnosticus von Meyer (242). Lateral-line canals always present (458) on the skulls as deeply impressed grooves which, in life, were possibly roofed-over by a cartilaginous or other connective-tissue membrane. The sensory organs undoubtedly being supplied by the superficial ophthalmic branch of the trigeminal nerve, branches of which pierced the cranial elements near the grooves, no evidence of such openings in the bottoms of the grooves; the condition probably being analogous to Hydrolagus colei and other chimÆroids. VertebrÆ stereospondylous, with well-developed neural arches from which projected the well-developed zygapophyses, sometimes slightly amphicoelous and pierced for the notochord, such forms being uncertainly placed in the group. Tail unknown, possibly short. Limbs and girdles well developed (243), phalangeal formula unknown; carpus osseous and tarsus unknown. Pectoral girdle composed of osseous scapulÆ, clavicles, interclavicle, coracoid (?); clavicles and interclavicle ventrally sculptured. Pelvic girdle composed of osseous pubis, ischium, and ilium (242), the pubis a small plate, in life largely cartilaginous, the three uniting by cartilaginous union to form the acetabulum. Ventral armature unknown, possibly wanting. Range: Pennsylvanian to Upper Triassic. Distribution: North America, Europe, Asia, Africa, and Australia. Family MASTODONSAURIDÆ Huxley, 1863. Huxley, Quart. Jour. Geol. Soc., XIX, p. 65, 1863. Lydekker, R., Cat. Fossil Reptilia Amphibia, pt. IV, p. 141, 1890. Skull triangular, and more or less elongated, with the cranial bones very strongly sculptured, the occipital condyles ossified (49), and large palatal vacuities; dentine of teeth with very complex plications (502); no bony rings (242) in sclerotic; and no ventral scutes. Bodies of vertebrÆ (49) fully ossified in the adult. There are large palato-vomerine tusks on the inner side of the maxillary teeth; and the palatines run parallel to the maxilla. The mandible has a large postarticular process; and there is a small inner series of mandibular teeth. In the type genus the pubes are separate from the ischia, and do not enter into the formation of the acetabulum; and the sacral ribs form kidney-shaped disks (393). Represented in North America by a single tooth from the Carboniferous of Kansas. Described by Williston as Mastodonsaurus sp. (Kans. Univ. Quart., VI, pp. 209-210, pl. XXI). Represented in the Triassic of Wyoming by Anaschisma browni, Branson (49). Mastodonsaurus sp. indet. Williston, Kans. Univ. Quart., VI, p. 209, 1897. The specimen preserved comprises the entire crown of a single vomerine (?) tooth, 38 mm. in length by 14 mm. in diameter at base (pl. 21 , fig. 6) . The immediate tip had been partly worn away in life, but was acuminate. It is composed of a dense blackish material, with the exterior smooth, shining black. It has about 20 narrow A hemisection of the tooth was made near the middle, showing a structure most remarkably like that of Mastodonsaurus; so nearly alike, in fact, that there is no difference from the large figure given by Owen of a section of Mastodonsaurus (502). The discovery of this tooth in the Kansas Coal Measures is of great interest, proving, as it does, the presence of true labyrinthodonts from a lower horizon than elsewhere recorded. The discovery of Eobaphetes kansensis Moodie in the Carboniferous of Washington County (473) would seem to indicate another labyrinthodont. The tooth from Louisville was possibly not the first evidence of labyrinthodonts in North America, since the discovery by Marsh of Eosaurus acadianus from the Coal Measures of Nova Scotia, possibly a member of the Stereospondylia, antedates this discovery 30 years. The specimen is preserved in the Museum at the University of Kansas. AMPHIBIAN FOOTPRINTS FROM THE COAL MEASURES. Footprints may be said to be fairly common in the Coal Measures of North America. Especial attention has been given to the classification of these objects by G. F. Matthew (408-413), Dawson (208-210) and others. Hay (317, pp. 538-553) has given a catalogue of all the species described from the Coal Measures of North America, to which the reader is referred for further information in regard to these interesting evidences of former animal activities. The writer has not been interested in the taxonomy of footprints, but has studied such as have come to his notice (465). A description of the species Dromopus agilis Marsh (fig. 43) is given here, because there is a large slab in the University of Kansas Museum which has not been figured. Since the chief interest in the present contribution is morphology, footprints are thus scantily dealt with. Leidy (374), Dawson (207), Moodie (465, pl. LXIV, fig. 1) and others have given various brief descriptions of Coal Measures footprints, probably all of which are evidences of Amphibia which are otherwise unknown. Dromopus agilis Marsh. Marsh, Jour. Sci. (3), XLVIII, p. 82, pl. ii, fig. 3; pl. iii, fig. 3, 1894. Hay, Bull. U. S. Geol. Surv., No. 179, p. 543, 1902. Type: Specimen in the Yale University Museum. Horizon and locality: Osage limestone (Coal Measures), near Osage City, Kansas. In 1894 Professor Marsh described a collection of footprints which he had secured from Professor B. F. Mudge, of Manhattan, Kansas, who had collected them in Osage County, Kansas, in a rock quarry, having purchased a large quantity of rock from the quarrymen for that purpose. A preliminary note by Mudge (490) was published in the Transactions of the Kansas Academy of Science and late "The impressions are well preserved in a calcareous shale, which separates readily into thin slabs, each representing a surface of the beach at the time the footprints were made upon it. A few shells in the shale are sufficient to prove that the formation is marine (no shells are evident in the slab at the Museum of the University of Kansas, but the slab is quite arenaceous). Trails of annelids, or perhaps of other invertebrates, are seen on some of the surfaces. The footprints of vertebrate animals, however, are of paramount importance, and the large number and variety of these here recorded on a single surface, if they could be rightly interpreted, would form an interesting chapter of land vertebrate life in the Carboniferous, about which so little is at present known." Fig. 43.—Footprints of Dromopus agilis Marsh, from the Coal Measures of Osage County, Kansas. Original slab in University of Kansas Museum. Greatly reduced. Professor Marsh's description of Dromopus agilis is as follows: "The third series of footprints is of special interest, and indicates an animal very distinct from the two already described. The diagram represents the impression of the phalanges sufficiently in detail to indicate (406) their number and general form. A striking feature in the fore and hind feet of this animal was the long, slender digits terminated by sharp claws. Another point of interest, as recorded in the footprints, is that the animal in walking swung the hind feet outward, and so near the ground that the ends of the longer toes sometimes made trails in the mud, marking accurately the sweep of the foot. This would seem to indicate a comparatively short hind leg, rather than the long, slender one which the footprints themselves naturally suggest. "The animal which made these interesting footprints was probably a Lacertilian rather than an Amphibian, but there is also a possibility that it was a primitive Dinosaur." Further on Professor Marsh remarks (p. 84): "So far as at present known, land vertebrate life began in the Carboniferous age, no footprints of other remains of this kind having been detected below the Subcarboniferous. That such remains will eventually be found in the Devonian, there can be no reasonable doubt, and perhaps even in the Silurian, if the land surfaces then existing can be explored." This last statement of Marsh's was, of course, partly demonstrated by the discovery of footprints in the Devonian rocks of Pennsylvania, which he described in 1896 as Thinopus antiquus. The footprints of Dromopus agilis Marsh which are preserved in obverse in the University of Kansas Museum are of considerably
The slab is No. 5 of the University of Kansas Museum of Natural History, collected in 1873 by Professor B. F. Mudge at Osage, Kansas, and presented by him to the museum in 1875. The following list of Carboniferous amphibian (?) footprints is compiled from Hay's Catalogue of Fossil Vertebrates of North America. It is given here for the sake of completeness. Three types of amphibian footprints are described in the body of this work and they constitute the kind of material which an ichnologist has for the basis of his conclusions. The material is not very satisfactory for the morphologist, though much can be determined as to the foot structure.
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