Cope, Geol. Surv. Ohio, II, pt. II, p. 368, pl. xliii, fig. 1, 1875. Type: Specimen No. 8617 G, American Museum of Natural History, collection of Dr. J. S. Newberry. Horizon and locality: Linton, Ohio, Coal Measures. This species is established by remains of 2 individuals, one embracing 16 and the other 14 vertebræ, with ribs. The neural arches, viewed from above, have a =V=-shaped outline posteriorly, from the fact that the broad zygapophyses meet on the median line and spread out distally over the broad anterior ones adjoining. The latter appear to be somewhat concave and to border the former exteriorly as well as inferiorly. The base of the neural spine extends to the posterior emargination, but not quite to the anterior. The breadth of the dorsal vertebræ above is equal from the emargination behind to the anterior margin of the anterior zygapophyses. The ribs are long for an amphibian, but not long for a reptile. They are well curved, chiefly near the proximal extremity. The longest found, measured by a cord, equals two and two-fifths vertebræ. These vertebræ, measured along the median line above, equal 11 lines; one of these is 3.6 lines in width above. This animal has been, like _Amphiuma_, a snake-like amphibian, but was probably still larger. How near the affinities to this genus may be can not now be determined, owing to the want of many important parts of the skeleton, but it differs in the important feature of large, well-developed ribs. The size of the vertebræ would indicate a body of the size of the common rattlesnake (_Crotalus horridus_) and too large for _Brachydectes newberryi_, which is only known from jaws. [Illustration: Fig. 32.--Drawing from Cope's figure of _Molgophis brevicostatus_ Cope, × 0.5] =Molgophis brevicostatus Cope.= Cope, Geol. Surv. Ohio, II, pt. II, p. 369, pl. xliv, fig. 1, 1875. Moodie, Proc. U. S. Nat. Mus., 37, p. 27, 1909. Type: Specimen No. 8341 G, Amer. Mus. of Nat. History. Horizon and locality: Linton, Ohio, Coal Measures. Represented by portions of the vertebral column of several individuals. One of these includes 9 pairs of ribs, with vertebræ, and another 13 pairs. The vertebræ are subquadrate in section, and the concavity of the two articular faces is not deep. They support strong lateral ridges separated by deep concavities. The heads of the ribs are somewhat contracted, and the shafts present outward a tubercular angle at a distance of one-fourth the length from the head. The remaining part of the shaft is stout, nearly straight, and gradually contracts to an obtuse extremity. It possesses a narrow medullary cavity. In none of the specimens is there any trace of abdominal armature, but abundant remains of the contents of the abdominal cavity, in proper position, are preserved on the blocks. This species is more massive than Molgophis macrurus, and the ribs are shorter, thicker, and less curved.