178 CRETACEOUS AND TERTIARY FISH. 



This was a large species, known only from its rostrum, and 

 especially characterized by its depressed form with the dentary 

 surfaces on one plane. 



Formation and locality. Only the type known, described above, 

 from the greensand of Burlington County (C. H. Budd). Not 

 seen by me. 



ISTIOPHORUS HOMALORHAMPHUS (Cope). 



Histiophorus homalorhamphus Cope, Proc. Boston Soc. Nat. Hist., XII, 1869, 

 p. 310, Eocene or Miocene Greensand near Squankum, N. I. 



Rostrum, in general form nearly cylindrical, tapering slightly, 

 depressed above and below, though former surface more so, thus 

 forming wide ovoid in transverse section with lesser diameter 

 one-seventh greater or horizontal at its base. Near end of ros- 

 trum vertical diameter but little less that of horizontal. Upper 

 surface evenly convex, and each side slopes down rather evenly 

 below somewhat in a plane, these surfaces approximating toward 

 end of rostrum and intermediate space at first moderately convex, 

 but gradually becoming very constricted.' At base two small ap- 

 proximated foramina a little below middle in vertical diameter. 

 Surface of rostrum entirely minutely porous. Length 170 mm. 



The examples described above seem to be identical with Cope's. 

 This species differs from /. antiquiis in its more cylindrical form 

 and having the dentary surfaces on two planes. The following 

 characters are gathered from Cope's account. 



Rostrum nearly cylindrical, with a slight depression, trans- 

 verse diameter exceeding vertical by less than one-eighth of 

 former. Dentigerous inferior bands not separated by a groove, 

 width of each two-thirds lesser diameter, each forms with other a 

 strong obtuse angle and basally flattened, then curved upw r ards at 

 external margin. Alveolae numerous, small, 5 in one-tenth of an 

 inch. Base broken, but longer diameter 4^/3 of length. Surface 

 of base not dentigerous, with numerous anastomosing striae. 

 Length about no mm. 



Formation and locality. Eocene or Miocene greensand near 

 Squankum in Monmouth County (W. S. Vaux). Only known 

 from the above-described type, an osseous muzzle, and three 



