1 J^Q 



1SG9.] [Cope. 



alveoli for two representatives of teeth on each side, Indicate a peculiar 

 character of the genus. The two largest alveoli occupy the extremity of 

 the symphysis, looking upwards and forwards. They are closely approx- 

 imated, and are together wider than the mandible immediately behind 

 them, which expands to support them. They are shallow, with rugose 

 floor, which is somewhat elevated medially, and perforated by numerous 

 nutritious foi-amina. The other alveolae are nearly twice the middle of 

 the mandible behind the anterior pair. They are much smaller tlian the 

 latter, and equally shallow, and of a longitudinal ovate form; the fundus 

 is rugose, not elevated, and furnished with nutritious foramina, which 

 are smaller than those of the edentulous gum. 



That true teeth occupied these positions, appears to me doubtful, from 

 their shallowness, and small foramina. I rather suppose them to have 

 been knobs or bosses, possibly corneous in structure. The edges of the 

 mandible resemble those of such edentulous Cetacea as Hyperaodon and 

 Xiphius, and indicate not very distant relationships to tooth bearing 

 types. The mental foramina are large and subdivided, so that the largest 

 and posterior opening is inferior, the superior anterior. 



The affinities of this very curious genus appear to be in a general Avay 

 with the aberrant Cetacea. The nearest types appear to be on the one 

 hand Sirenia, and on the other, Squalodon. How remote it may be from 

 either, it is difficult to state; of approximation to either little can be said. 

 Should the posterior part of the ramus exhibit teeth, their character 

 would indicate its Sirenian or Cynorcoid relationships. We can now only 

 indefinitely regard it as a shore loving Cetacean, with a long slender 

 beak, which it must have used much as nippers, perhaps probing mud or 

 deep cavities, but for what kind of food it is difficult to imagine. 



Anoplokassa forcipata, Cojye. 



The length of the portion of the mandible described is seven inches, 

 six lines. The transverse diameter differs very little to a point half way 

 between the alveoloe, where it is gently contracted; it is then slightly ex- 

 panded, and presents an obtusely projecting outline at the extremity. In 

 profile the symphyseal extremity curves gently upwards from the jioint 

 where it first contracts, so that the ridge separating the alveolae is quite 

 elevated. In transverse section the fragment is almost practically an 

 isosceles spherical triangle, with a straight superior side. The superior 

 face is however slightly convex in section, and a little elevated above the 

 dental grooves on each side. There is a slight groove on each side of the 

 symphysis below, which becomes Very strongly marked distally. Tliey 

 diverge and continue to the extremity through the mental foramina, and 

 reaching the iipper surface nearly ;meet again. They enclose a strong 

 symphyseal ridge, which is distally divided by a groove. 



Meusuremerds. 



m. 



Length of fragment 1 !)20 



•' to second alveolus OToo 



" of " " 0140 



" of first " 0240 



