112 CATALOG OF POSSIL FISHES IN THE MUSEUM 



E 2432 Four right lower dental plates ranging from 21 to 43 mm. 

 in length. Two of them (PL 36, fig. 7; PI. 37, fig. 8), 

 show the inner face better preserved than in any other 

 specimen. This is very deep, giving the plate in inner 

 view a somewhat semilmiar appearance. 



E 2433 A large left lower dental plate (PL 37, fig. 7). 



That this species occm-s in rock of Tully age, is evidenced by the 

 following : 



E 2402 Upper dental plate, 17 mm. in length, 



Pyrite layer of the Tully horizon, Cazenovia Creek, 

 Springbrook, N. Y. Collected by W. L. Bryant. 



Ptyctodus compre'ssus ? Eastman 



E 1892 An imperfect dental plate. 



Hamilton limestone (Mid. Devonic); Milwaukee, Wis. 

 Collected by Mr. Edgar E. Teller. 



E 1893 An imperfect dental plate. 



Formation and locality same as preceding. 



Ptyctodus howlandi, n. sp. 



(PL 38; text-fig. 38) 



E 1919 Type. — Left lower dental plate. Length 102 mm.; depth 



at center, 22. 



Horizon and Locality. — Conodont Bed (Genesee); Eighteen Mile 

 Creek, near North Evans, Erie County, N. Y. Collected by W. L. 

 Bryant. 



Dental plate elongated, shallow (in outer view), its hinder third 

 rising gently toward the posterior extremity. Depth at middle of 

 element contained 4I times in its length. Oral margin consisting 

 of a prominent "beak," followed by a cutting edge extending to end 

 of second third of the oral margin, at which point there is a depression 

 formed by the opposing upper tritor; then, in last third of element, a 

 broad tritoral area, which rises from inner face outward so as to form 

 with this face a sharp edge especially pronounced in hindermost por- 

 tion of the tritor. Tritor covered with punctse, which in its middle 



