1895.] 141 [Cope. 



of Cetotherium leptocentrum and C. ceplialus. It compares more closely in 

 dimensions with tlie C. polyporum from the Chesapeake formation of 

 North Carolina. From the last named, audfrom the C cephalus, it differs 

 in the robust form of the ramus, resembling in this respect rather such 

 species as C. palceatlanticum, 8. priscus (Leidy), and S. expansus. 



The fragment representing the S. dnrkianns is from the part of the 

 ramus anterior to the base of the coronoid process, and is about 350 mm. 

 in length. Both faces are convex, but the external is more strongly so 

 than the internal. The superior part of the latter is, however, not hori- 

 zontal as in the 8. priscus, nor is the internal face subhorizontal as in 

 8. expansus. The two faces unite above at an obtuse angle, which if 

 perfect, would be nearly right. The inferior edge is on the contrary a 

 ridge which would be acute were it not rounded. The section of the 

 ramus is therefore lenticular, with one side more convex than the other. 

 Posteriorly the external convexity becomes greater, and the internal con- 

 vexity rises towards the base of the coronoid, leaving a gentle concavitj' 

 above the inferior border. The external foramina are large, distant, and 

 only a little further below the superior ridge than those of the inferior in- 

 ternal row. The latter are in two series ; those of the superior smaller 

 and quite near the superior edge ; the others larger and situated lower 

 down, and separated by intervals of about 40 mm. No trace of Meckelian 

 or alveolar grooves. 



Measurements. 



MM. 



vertical 95 



transverse 72 



I vertical 114 



\ transverse 99 



Diameters at distal end. . . 

 Diameters near coronoid. 



The presence of two internal series of foramina distinguishes this spe- 

 cies from any of those known to me. The rami are less compressed than 

 those of the G. pusillum, while the external pasition of the external fora- 

 mina distinguishes it from the 8. priscus (Leidy). The presence of an 

 acute-angled ridge below distinguishes it strongly from the G. palwatlan- 

 ticum. The species was larger than the Cetotherium megalophysum above 

 described, having probably attained a length of forty feet. 



I have dedicated it to Prof. William B. Clark, of the Depirtment of 

 Geology and Paleontology of the Johns Hopkins University, to whom I 

 am under obligations for the opportunity of studying most of the mate- 

 rial here described. The label attached to the specimen states that it was 

 dredged up near Point-no-Point, Chesapeake Bay, and was presented to 

 Johns Hopkins University by Conrad Miller. 



Ulias moratus, gen. et sp. nov. Plate vl. Fig. 1. 



Char, gen — Mandible with the ginglvodental canal open throughout 

 most of its length, closed only near its apex. Gingival foramina repre- 

 sented by a few orifices on the alveolar border near the distal extremity. 



