70 NEW YORK STATE MUSEUM 



Pterygometopus callicephalus Hall sp. 



Phacops e a 1 1 i c e p h a 1 u s Hall. Pal. N. Y. 1847. 1:247 

 Numerous cranidia and pygidia of this species were found in 

 the gray crystalline and black compact limestone pebbles, and a 

 few also in the reddish gray, hard limestone pebbles. P. calli- 

 cephalus ranges from the Lowville limestone into the Tren- 

 ton beds and occurs from Canada and New York to Minnesota 

 and the Winnipeg region. (Groups 5, 6, 7) 



LEPERDITIA Kouault 



Leperditia fabulites Conrad sp. 



Cytherina fabulites Conrad. Acad. nat. sci. Phil. 

 Proc. 1843. 1:33(2 



PL 5, fig. 19, 20 



A small number of this robust ostracode type were found in the 

 gray crystalline limestone boulders of Rysedorph hill, some of 

 them of considerable size, as shown by the natural size figure of 

 the largest specimen (pi. 5, fig. 19). The writer does not believe 

 that much can be added to the exhaustive description given by 

 Ulrich, 1 who had a large amount of material at command,. 

 A peculiar feature is shown by the largest specimen figured, 

 which, probably, has some relation to the two series of email 

 papillae observed by Ulrich on the inner side of the anterior and 

 posterior thirds of the right valve. The specimen froon Ryse- 

 dorph hill, which is also a right valve, shows on the outside, in 

 a position corresponding to the internal papillae, six radiating 

 furrows which, beginning at the internal margin of the small, 

 short, flat border, into which they enter, become shallower and 

 narrower toward the margin, The flat rectangular interspaces 

 are each marked ' by a very distinct flabellate group of striae 

 (fig. 20). 



Leperditia fabulites is a characteristic and common 

 fossil of the Lowville limestone in New York about Lake Huron 

 and other parts of Canada, Kentucky, Illinois, Tennessee, Wis- 



i Geol. Minn. Pal. 1897. v. 3, pt 2, p. 624 f. 



