FOSSILS OF THE DEVONIAN. 



177 



In making an original generic reference, I would place the species under 

 Modiomorpba, as it is more closely related to the genus as defined by Pro- 

 fessor Hall (Prelim. Notice Lam. Shells, 1870. 8vo., pam., p. 72) than 

 to Sanguinolites, as restricted by him to American species. For the present, 

 Mr. Meek's provisional reference is retained. 



Formation and locality. Lower Devonian of Atrypa Peak, Eureka Dis- 

 trict, Nevada. 



Sanguinolites ventricosus W. & W. (Sp). 

 Plate xv, fig. 13. 



Orthonota ventricosa White & Whitfield, 1862. Proc. Boston Soc. Nat. Hist., vol. 



viii, p. 297. 

 Sanguinolites ventricosus Miller, 1877. Cat. Ainer. Pal. Foss., p. 203. 



Hall, 1883. Pal. N. Y., vol. v, pt. 1 ; Plates and Descriptions, 

 p. 16, pi. Ixvf, figs. 36-42. 



The Nevada shell possesses all the specific characters of the examples 

 of this species from the Burlington sandstone of Iowa, differing only in the 

 more angular umbonal ridge, and not quite as expanded posterior end; 

 features reduced or enlarged by the nature of the sediment in which the 

 shells are embedded. A species referred to this from the Chemung Group 

 of New York has sharp concentric lines instead of the more rounded lines 

 of the Burlington species. 



Formation and locality. Middle to Upper Devonian, Rescije Hill, west 

 of Rescue Canon, Eureka District, Nevada. 



Genus CONOCARDIUM Bronn. 



X 



Conocardium Nevadensis, n. sp. 

 Plate xvi, figs. 4, 4 a. 



Shell small, cordate when viewed from the anterior end, and subtrig- 

 onal on a side view; anterior half ventricose, sloping away rapidly to the 

 narrow posterior extremity and obliquely truncate anteriorly, the anterior 

 slope being more or less concave below the rounded umbonal angle; beaks 

 rising above the hinge-line, incurved; hinge-line straight, forming an angle 

 of about 80 with the posterior, and 110 with the anterior, margin; hiatus 



not observed in the united valves, but from the outline of the single valve 

 12 c D w 



