COPE.] PALEONTOLOGY EOCENE PEEIOD. 459 



OEOTHEEIUM, Marsli. 



Amer. Joum. Sci. Arts, 1872, p. 217. 



Orotherium index, sp. nov. 



Represented by both mandibular ramis, with many of the molars in 

 good preservation. These number P. m., 3 ; M., 3. The last premolar is 

 somewhat like the first molar, but has but one posterior tubercle, and 

 adds a cingular projection in front of the anterior pair. The first pre- 

 molar has two roots ; the second is comi)ressed and with a broad heel 

 behind. In the molars, the anterior tubercles are connected by a cross- 

 ridge ; the posterior are a little more distinct from each other. The 

 inner anterior tubercle is obtuse, but not bifid, and its base is connected 

 ■with the apex of the posterior outer by a diagonal ridge. There is a 

 small median jiosterior tubercle on the M. 2, and a large heel on the 

 last molar. It supports a conic tubercle, which is connected by sharp 

 ridges with the tubercles preceding it. There is a cingulum on the outer 

 face of the true molai^s, which does not extend on the base of the tuber- 

 cle of the posterior pair. 



Measurements. 



M. 



Length of molar series : 0.0350 



Length of first premolar 00:52 



Length of third premolar ■ ,0055 



Width of third premolar 0040 



Length of second molar : ,0065 



Width of second molar 0045 



Length of last molar 0098 



Deptli of ramus at first premolar 0021 



Depth of ramus at second molar 0023 



PISCES. 

 EHmEASTES, Cope. 



Hayden's Annual Eeioort, 1872, p. 6*38. 



Ehineastes pectinatus. Cope, Bullet. U. S. Geol. Surv., No. 2, 1874, 

 p. 49. 



This catfish is represented by a single specimen, which includes only 

 the inferior view of the head and body anterior to the ventral fins. 

 These exhibit characters similar in many respects to those oH Amiurus, 

 Eaf., but the iuteroperculum, the only lateral cranial bone visible, dis- 

 plays the dermo-ossifled or sculptured surface of the Eocene genus, to 

 ■which I now refer it. Other characters are those of the same genus. 

 Thus, the teeth are brush-like, and there is an inferior limb of the post- 

 temporal bone, reaching the basi-occipital. The modified vertebral mass 

 is deeply grooved below, and gives off the enlarged diapophysis that 

 extends outward and forward to the upper extremity of the clavicle. 

 The patches of teeth on the premaxillary are separated by a slight 

 notch at the middle of the front margin The teeth are minute. The 

 four basihyals and the elongate anterior axial hyal are distinct ; also, 

 the ceratohyal with its interlocking median suture. The number of 

 branchiostegal radii is not determinable ; three large ones are visible. 

 The mutual sutures of the clavicles and coracoids are interlocking, and 

 their inferior surface disijlays grooves extending from the notches. The 



