26 A COXTEIBUTIOX TO THE LoWER DeVOXIAN FaUXAS OF MaRYLAXD 



Family BELLEROPHONTIDAE 



Genus BELLEROPHON Montfort 



Belleeophox cf. aueiculatus Hall 



Plate LX.XIX, Figs. 1, 2 



Bellerophon aurictilatus Hall, 1852, Nat. Hist. N. Y., Pal., vol. li, p. 334, pi. 

 Ixxvi, figs. 7a, h. 



Description. — " Convolute ; 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 ]\Ir. Eoeder are tentatively re- 

 ferred to in 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. Eoeder. 



Genus CYRTOLITES Conrad 



Cyrtolites expaxsus Hall 



Plate LXXIX, Figs. 5, 6 



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



figs. 4, 5, 1861. 

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



pl. 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 ventricose ; subcarinate on the dorsum : 

 aperture nearly circular. Surface of cast marked by faint transverse 

 ridges and finer longitudinal stria^." Hall, 1859. 



" . . . . characterized : 1 by the sharply concentric lamellse of the sur- 

 face; 2 by the broadly expanded aperture; 3 by the well-defined median 

 ridge on the earlier parts of the shell, on which the stride have a pronounced 

 retral bend, the ridge being obsolete at the margin." Clarke, 1900. 



