MAKYLAND GEOLOGICAL SURVEY 25 



Width of premaxillary 6 lines (12 mm.) 



Width superior face of maxillary 4.75 lines ( 9.50 mm.) 



Width palatine face of maxillary 4.5 lines ( 9 mm.) 



" Three teeth are referred with much probability to this species. 

 The fangs are from equal to twice the length of the crowns, and are 

 much compressed, widening downwards, and more or less prolonged at 

 one inferior angle, in the same plane. The crown, compressed trans- 

 versely to the root, and expanded above the base, straight or slightly 

 curved in the direction of its plane. Enamel smooth, edges obtuse. 

 The compressed fang corresponds to the longitadinal alveolus while 

 the transverse dilatation of the crown is similar to the form of those of 

 Platanista. 



Length of the longest specimen 12 lines (24 mm.) • 



Length of the crown 5 lines (10 mm.) 



Width of fang 3 lines ( 6 mm.)" 



Occurrence. — Calyekt Foematiox. Charles county near the Patux- 

 ent river. 



Collection. — The type specimen is preserved in the Museum of the 

 Academy of Natural Sciences of Philadelphia. 



Genus LOPHOCETUS Cope. 



" Temporal fossa truncated by a horizontal crest above, prolonged 

 backward and bounded by a projecting crest, which renders the occi- 

 pital plane concave. The same crest prolonged upward and thickened, 

 each not meeting that of the opposite side, but continued on the inner 

 margins of the maxillary bones, turning outwards and ceasing opposite 

 the nares. Front, therefore, deeply grooved. Premaxillaries separated 

 by a deep groove. Teeth with cylindrical roots." Cope, 1867. 



The genus was regarded as belonging very close to the living genera 

 Pontoporia and Inia. " The resemblance to Inia is the closest. The 

 only feature which renders a generic distinction certain is the cylindric 

 form of the posterior alveolae, which renders it probable that the teeth 

 were not furnished with lobes as in Inia." 



