466 Systematic Paleontology 



Description. — "Convohite; volutions somewhat flattened from the 

 dorsal side ; last volution rapidly enlarging ; aperture expanded, curving 

 outwards and nearly reflexed at the lateral angles. The remains of a 

 carina, with arched striae diverging therefrom, are visible upon the dorsal 

 side." Hall, 1852. 



Several specimens in the collection of Mr. Boeder are tentatively re- 

 ferred to this species. In general aspect they resemble Hall's figures very 

 closely, but are much smaller. Precise horizon unknown. 



Diameter of shell 1.5 cm. ; of aperture 1.5 cm. 



Occurrence. — Helderberg Formation. Cumberland. 



Collection. — George M. Boeder. 



[Ohern.] 



BeLLEROI'HON HELDERBERGI^gi n. sp. 



Plate LXXIX, Figs. 3, 4 



Description. — Convolute, volutions somewhat flattened dorso-ventrally ; 

 last volution expanding rapidly, aperture expanded. Umbilicus small. 

 Dorsal carina pronounced. Surface ornamentation unknown. 



This species difl;ers from Bellerophon auriculatus in its more rapidly 

 expanding volutions and distinct dorsal carina. 

 Diameter of shell 1.4 cm.; of aperture 1.5 cm. 



Occurrence. — Helderberg Formation, Keyser Member. Cash Valley. 

 Collection. — U. S. National Museum. 



[Maynard.] 

 Genus CYRTOLITES Conrad 

 Cyrtolites expansus Hall 

 Plate LXXIX, Figs. 5, 6 



Cyrtolites ? expansus Hall, 1859, Nat. Hist. N. Y., Pal., vol. ill, p. 479, pi. cxiv, 



figs. 4, 5, 1861. 

 Cyrtolites expansus Clarke, 1900, Mem. N. Y. State Mus., vol. ill, No. 3, p. 28, 



pi. iii, figs. 20-23. 



Description. — " Shell obliquely depressed conical ; the apex incurved, 

 but making scarcely or no more than, a single volution, very rapidly ex- 

 panding from the apex ; the body vantricose ; subcarinate on the dorsum : 



