220 Twenty-fourth Report on the State Museum. 



Crania setigeea n. sp. 



Plate 7, figs. 13, 14. 



Shell small, suborbicular ; length greater than width; cardinal 



margin nearly straight. Dorsal valve convex ; beak elevated, pointed, 



situated nearly one-third the length of the valve from the cardinal 



border. 



Surface marked by comparatively coarse pustules or setae, which 

 are more distant near the margin of the shell. 



^ The surface-structure and the prominent pointed beak are suffi- 

 ciently characteristic to distinguish this species from any other form 

 of the genus found in the rocks of this age. 



Formation and locality. In limestones of the period of the Tren- 

 ton limestone, near Mineral Point, Wisconsin. 



Crania scabiosa n. sp. 

 Plate 7, fig. 15. 

 Shell somewhat less than medium size, usually discoid or little ele- 

 vated, but sometimes prominent, irregular in outline; margin thick- 

 ened. Apex of dorsal valve eccentric, varying in different individu- 

 als. Surface of valve having usually strong lamellose lines of growth, 

 which are sometimes obscured by the roughness of the substance to 

 which the specimen is attached, showing through the shell or causing 

 it to grow irregularly, by which it often assumes the features of the 

 foreign body. Yentral valve unknown. 



This species is not uncommon ; usually found attached to shells of 

 otlier Brachiopoda, and sometimes on Cn^xETEsand other substances. 

 The valves of Orthis lynx, Orthis OGcidentalis and Streptorhynchits 

 jjlanumbona are often found with several individuals so crowded 

 together as to give quite an irregular outline to the specimens. 



Formation and localities. In the Hudson-river group, at Cincin- 

 nati, Oxford and Lebanon, Ohio ; also on the banks of the Ohio 

 river opposite Westport, Kentucky, 



Crania L^lia n. sp. 

 Plate 7, fig. 16. 

 Shell small, discoid or moderately convex on the upper valve, 

 somewhat narrowed towards the cardinal border. Apex of the dorsal 

 valve minute, not prominent, situated about one-third the length of 

 the valve from the cardinal margin. 



Surface marked by fine but very sharply elevated radiating striae, 

 which are sometimes tortuous, and frequently increased by implanta- 

 tion. Yentral valve and interiors not observed. 



