(No. 8607, American Museum of Natural History.) mm. Length of skull as preserved 40 Anterior width across orbital region 22 Greatest width of the skull 33 Length of clavicle 18 Greatest width of clavicle 9 Still a third specimen of this species is possibly represented by a nearly complete skull of a small individual which exposes the mandible and the ventral portion of the skull. The remains are crushed flat, though not at all distorted. It is quite possible that the present specimen represents a distinct species, but only a small portion of the dorsum is present and the shape of the cranium is indistinct, so it is retained in this species. The portion of the skull shows the sculpture to be quite similar to that of _Erpetosaurus acutirostris_, so far as the species is known; and the skull apparently tapers to a point anteriorly. It may be a dwarfed or immature form. The sculpturing of the jaw is such as we would expect of this species. The specimen is about half the size of the type. The palate of the skull is well preserved and is extremely interesting. The sutures separating the various palatal elements are not distinct. The parasphenoid is especially large and the exoccipitals are partly ossified, if we may judge by the projecting condyles. Anteriorly the parasphenoid contracts and then expands and on each side of the expanded part lie fragments of the palatines. To the right of the posterior end of the parasphenoid lies a portion of the dorsal element showing the cranial sculpture. The left mandible is somewhat displaced to the right of the skull, and crushed and weathered to such an extent that the sutures are entirely obliterated. There are 3 teeth, with indications of others. They are typically pleurodont and sharp and slender. The mandible tapers somewhat anteriorly and at the tip bears an elongate enlarged tooth. Measurements of the Third Specimen of Erpetosaurus acutirostris Moodie in the American Museum of Natural History. mm. Length of skull, as preserved 25 Posterior width of skull 15 Anterior width of skull 10 Width across occipital condyles 4 Length of mandible 25 Anterior width of mandible 2 Length of large tooth 1 =Erpetosaurus tuberculatus Moodie.= Moodie, Bull. Amer. Mus. Nat. Hist., XXVI, pp. 348-349, pl. lviii, 1909. Type: Specimen Nos. 8693 G and 8610 G, American Museum of Natural History. Horizon and locality: Linton, Ohio, Coal Measures.