4. Photograph of type of _Thinopus antiquus_ Marsh, the amphibian footprint from the Devonian of Pennsylvania. × 1/4. Courtesy of Dr. Lull. Original No. 784, Vale University Museum. ] =Cephalerpeton ventriarmatum Moodie.= Moodie, Kans. Univ. Sci. Bull., VII, No. 2, pp, 350-352, pl. 1, fig. 4; pl. 7, fig. 2, 1912. Type: Specimen No. 796, of Yale University Museum. Horizon and locality: Collected at Mazon Creek in 1871, near Morris, Illinois. The remains on which the present species is based consist of an almost entire skull, 26 consecutive vertebræ, both fore limbs, 20 ribs preserved on the right side of the body, and a portion of the ventral armature (plate 4, fig. 4). The skull is very broad posteriorly, its width being one-third greater than its length, with due allowance for crushing. A pineal foramen is not preserved. The sutures bounding the premaxillaries, the maxillæ, the nasals, the prefrontals, the frontals, a portion of the parietals, the squamosal, the supratemporal, the quadratojugal, and the quadrate (?) are fairly well preserved. The arrangement of these elements can be discerned by reference to figure 29. The prefrontals are unusually large and are triangular in shape. The supratemporal is also quite large. The surface of the skull bones is smooth and there is nowhere an indication of sculpture. [Illustration: Fig. 29. Skeleton of _Cephalerpeton ventriarmatum_ Moodie. × 1. _pf_, prefrontal; _cl_, clavicle; _m_, mandible; _h_, humerus; _j_, jugal; _mx_, maxilla; _or_, orbit; _ph_, phalanges of hand; _par_; parietal; _po_, postorbital; _r_, radius; _sp_, sclerotic plates; _u_, ulna; _vs_, ventral scutellæ.] Portions of 4 sclerotic plates are preserved in the right orbit. These measure 0.5 by 0.75 mm. The orbits are large and the interorbital space is less than the transverse diameter of the orbit. Thirteen teeth, apparently pleurodont, are preserved on the left maxilla. They are short, sharply pointed, smooth, and unequal. The first 2 left maxillary teeth from the anterior end are short; then follows a tooth which is one-third longer than these two; the fourth tooth is somewhat shorter than the third; the fifth and sixth are still shorter and are practically equal in size, though somewhat larger than the first two. The right mandible is preserved almost entire, though so badly eroded that little can be said of its structure. Impressions of 12 teeth are present on the mandible and all are, apparently, equal. The cotylus seems to have been far posterior and an angle of the mandible projected slightly back of the skull.