Maryland Geological Survey 317 



There is a single broken specimen in the Maryland Collection which is 

 26 mm. in length, 17 mm. wide and shows six annulations which are 

 about 3 mm. apart, not so strong and distant as those of S. crotalum, but 

 similar to the figures of S. nuntium. A bit of the test is preserved at 

 one end showing the fine, thread-like longitudinal striae, which alternate 

 slightly in size as is stated to be the case for at least some specimens of 

 this species,' with ten to twelve in a space of two mm., crossed by finer 

 transverse striae. 



Occurrence. — Eomney Formation, Hamilton Member. W. Va. 

 side Potomac Eiver 3 miles south of Cumberland. 



Collections. — Maryland Geological Survey; New York State Museum; 

 American Museum of Natural History. 



Spyroceras clarkei n. sp. 

 Plate XLI, Figs. 9-11 



Description. — An annulated broken, compressed specimen which has 

 a total length of about 60 mm., and diameter of about 22 mm., showing 

 three annulations on one side and five on the other, is referred to this 

 genus. The annulations are broadly I'ounded, about 10 mm. vertically 

 from the center of one to the center of the adjacent one and separated by a 

 broad, rounded sinus. Surface marked by distinct, raised, uniform, con- 

 tinuous longitudinal striae which are crossed by regular concentric striae 

 of nearly the same strength, forming a slight node at the point of inter- 

 section, both at about the same distance apart so that the surface is com- 

 posed of squares or rectangles with a height and width of about 1 mm., 

 inside of which on part of the surface are faint vertical and concentric 

 striae which are perhaps due to crushing. 



This species is somewhat similar to Spyroceras geneva Clarke from the 

 Onondaga limestone of New York ; ' but it differs in having a more slender 

 tube, much broader sinus between the annulations and longitudinal and 

 concentric striae of nearly equal strength, instead of the longitudinal 



' PaL N. Y., vol. V, pt. ii, pi. 43, explanation of fig. 7. 



' 13th An. Rep. State Geologist [N. Y.], 1894 [1895], p. 168, pi. 2, figs. 5-7. 



