NATURAL SCIENCES OF PHILADELPHIA. 419 



upper and lower inner ones. These pores correspond with the 

 mucous ducts of the lateral line observed in the scales of the type. 

 The teeth are numerously placed in a patch on the vomer, or at 

 least the roof of the mouth, and are short, conic, acute, and 

 smooth. They are discoverable as far backwards as the anterior 

 end of the jugular plates. The large opercular bones are smooth, 

 and the head is covered above with nearly smooth, thin scuta. 

 The head is wide behind, and though contracted forwards, the 

 muzzle is broadly obtuse. Irregular masses, perhaps remains 

 of cartilas^e, follow the skull in which a few ribs are scattered. 



The other specimen displays the smooth operculum patch of 

 vomerine teeth, and several separated scuta of the surface of the 

 cranium. These have rounded angles, one or more convex sides, 

 and very obscure radiating ridges. 



The characters relied on as indicative of the reference of Pep- 

 lorhina to the fishes, are (1) the presence of opercula like those 

 of Conchiopsis ; (2) the presence of jugular bones, and (3) of 

 oval imbricated scales ; (4) the absence of ambulator^' limbs. 

 The thin scutiform cranial bones, the dense patch of vomerine 

 teeth, and the mucous ducts of the bones and scales were all 

 ichthyic characters. As no limbs had been discovered in three 

 specimens preserved in the appropriate regions, their nature, if 

 existing, could not be determined at present. 



Prof. Cope brought before the Academy some results derived 

 from study of material obtained bj' him during the preceding 

 summer in the miocene formations of Colorado. He announced 

 the discovery of the first fossil monkey of the miocene of America, 

 giving it the name of Menotherium lemurinum. He regarded it 

 as allied to the Tomitherium of the Bridger Eocene, and as the 

 representative of the more numerous group of the lemuroids, 

 which he had discovered in the latter formation. He stated that 

 there are three tubercular molars and a sectorial-like premolar in 

 front of them ; that this tooth is preceded either by a more elongate 

 premolar with two roots, or by two single-rooted premolars. 

 The molars each support four tubercles in nearly opposite 

 pairs, the inner anterior connected with the outer posterior 

 by a diagonal ridge ; the last premolar compressed with obtuse 

 apex, broad heel, and anterior tubercle. Size that of a domestic 

 cat. Prof. Cope stated that his recent discovery of snakes, 

 lizards, and lemurs of forms allied to those previously discovered 

 by Prof. Marsh and himself in the Eocene of Wyoming, consti- 

 tuted points of affinity to the fauna of that period not previously 

 suspected. He also observed that he had discovered some addi- 

 tional species of Ruminantia allied to the musk, and to the Lepto- 

 meryx evansii, Leidy, which he named Hypisodus miuimus^ and 

 Hypertragidufi calcaratus^ and H. tricostatus. The first was the 

 least of the order, not exceeding a cat-squirrel in size. Hyper- 



