108 CATALOG OP FOSSIL FISHES IN THE MUSEUM 



Genus Ptyctodus Pander 



The Conodont Bed at Eighteen Mile Creek has yielded a wonder- 

 ful series of ptyctodotit den,tal plates and tritors, — without question 

 the largest number of perfect specimens ever obtained from any for- 

 mation, or, in fact, from all other formations put together. Three 

 species are represented here — Ptyctodus calceolus, the typical and most 

 widely distributed specie's, which ranges through the Middle and 

 Upper Devonic; P. compressus, a species hitherto known only by a 

 few imperfect elements from the Upper Devonic of Iowa; and P. 

 howlandi, a splendid, large species described here for the first time. 



Ptycotdus calceolus Newberry & W or then 



(PI. 34; PL 36, figs. I, 2, 10; PL 37, fig. 9) 



This species is represented in the Buffalo Museum by two series of 

 dental plates and tritors — ^one from the Hamilton of Milwaukee, and a 

 second and larger series from the Conodont bed at Eighteen Mile 

 Creek. 



a. Specimens from the Hamilton limestone (Mid. Devonic) ; Mil' 

 waukee. Wis. Collected and donated by Mr. Edgar E. Teller. 



E 1884 Right lower dental plate (PL 34, figs, i and 3). 



This specimen is of unusual size, being nearly 6 cm. in 

 length. It apparently belonged to an old individual; th,e 

 triturating surface is worn down below the level of the lat- 

 eral faces of the plate. 



E 1885 An isolated tritor. 



E 1886 An isolated tritor. 



E 1887 An isolated tritor. 



E 1888 Left upper dental plate. 



E 1889 Imperfect right lower dental plate. 



h. Specimens from the Conodont Bed (Lower Genesee) ; Eighteen 

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

 W. L. Bryant. 



