74 CRETACEOUS AND TERTIARY FISH. 



concave, and outer moderately convex. Ends of root widely 

 diverging, and lower edge usually a little emarginated medianly. 

 Cutting-edges of lower front teeth very sharp or blade-like along 

 each edge of crown for apical half. These teeth also differ in 

 often having no serratures, and others show one to twelve basally. 

 They also have a very swollen or protruding inner base, fre- 

 quently with a median sulcus, and the ends of the root are often 

 markedly unequal. Length reaches 4 cm. 



This is a strongly marked form, and only the median slender 

 lower teeth somewhat suggest hunts or Lamna, but are much 

 thicker. Most all of Agassiz's figures agree with my material. 



Formation and locality. I have examined the following from 

 New Jersey: Monmouth County 11 (P. D. Knieskern) ; Long 

 Branch 1 without donor; Pemberton 2 (T. M. Bryan) and Vin- 

 centown 1 (Bryan) in Burlington County; Mullica Hill in Glou- 

 cester County 1 (W. M. Gabb) ; Allowaystown 9 (H. C. Yar- 

 row) ; in Salem County 5 (P. Uhler). 



I have also examined a tooth in the Geological Survey collec- 

 tion from Shiloh in Cumberland County (E. Davis). [From 

 the above citation of localities the specimens are probably from 

 the Navesink-Hornerstown marl, the Manasquan marl of Cre- 

 taceous and from the Kirkwood formation of the Miocene, K.] 



Genus GLYPHIS Agassiz. 



Glyphis Agassiz, Poiss. Foss., Ill, 1843, p. 243. Type Glyphis hastalis Agassiz, 



monotypic. 

 Cynocephalus (Klein) Walbaum, Pet. Arted. Gen. Pise, III, 1792, p. 579- 



Type Squalus glaucus Linnaeus, second species, virtually restricted by 



Gill, Ann. Lye. N. Hist. N. Y., VII, 1862, p. 401. (Name considered 



inadmissible as simply a reprint, also preoccupied.) 

 Prionodon Miiller and Henle, Syst. Besch. Plag., 1838, p. 35. Type Squalus 



glaucus Linnaeus, first species. (Name preoccupied.) 

 Prionace Cantor, Journ. Asiat. Soc. Bengal, XVIII, 1849, p. 399. Type 



Squalus glaucus Linnaeus, virtually as this name is proposed to replace 



Prionodon. 



Body slender. Head rather long, slender. Teeth in both jaws 

 strongly serrated in adult, those in upper broad and lower nar- 

 rower, straight and claviform. No spiracles. Embryo not at- 

 tached to uterus by a placenta. First dorsal large, inserted 



