220 Peculiar Fossils from the Chemung Rocks. 



2. Spiraxi§ Randalli, n. sp. 



Pl. XVIII, Figs. 2, 3. 



Body fusiform, three or four inches in length by six to eight lines in di- 

 ameter ; surface marked by two revolving and closely approximated ridges, 

 which below are broad and flattened or rounded, and separated by narrow 

 furrows, above acute and narrow, separated by broader furrows. 



From 8. major this species may be distinguished by its smaller size, its 

 somewhat curved or sinuous form, and the closer approximation of the 

 raised ridges, which are also more flattened and relatively broader. 



Formation and locality, Chemung Group, Warren, Penna. , where it was 

 first obtained by Mr. F. A. Randall, to whom it is dedicated. 



Since the above descriptions were written, Prof. James Hall, of 

 Albany, and Prof. H. S. Williams, of Cornell University, have 

 kindly sent to me for examination the considerable number of 

 specimens of Spiraxis which they have obtained from the Che- 

 mung rocks of Northern Pennsylvania and Southern New York. 

 Of these, all those received from Prof. Hall represent the species 

 8. Randalli ; none are more complete than those now figured, 

 and none exhibit characters which throw any light on the bio- 

 logical relations of these fossils. Among the specimens sent by 

 Prof. Williams, is one larger than the others, much curved and 

 flattened and having the spiral ridges relatively broad and flat. 

 It approaches most nearly to 8. Randalli and may be only a 

 phase of that species, but more material will be required before 

 this question can be settled. 



It is to be hoped that by the publication of this notice of these 

 singular organisms, the attention of those who are making col- 

 lections from the Chemung rocks will be specially directed to 

 them, and that by the discovery of specimens which are better 

 preserved, or by tracing their connections or relations as they 

 lie in the rock, their true nature may be determined. 



The originals of the figures now given are in the Geological 

 Cabinet of the School of Mines of Columbia College. 



