66 PROCEEDINGS OF THE ACADEMY OF 



guislied hy its remarkable alation extending forward from the 

 angular umbonal slopes. 



I have seen no specimens of our shell quite entire at the ante- 

 rior end, but it is evident that there was a slender projection 

 somewhat like that of C. aliforme of Sowerby, though it may 

 not have been so long as in that species. 



Locality and ^josition. Columbus, Ohio. Corniferous division 

 of the Devonian. 



SOLENOMYA (JANEIA) VETUSTA, Meek. 



Shell of medium size, transversely sub-oblong or narrow sub- 

 elliptic, the length being a little less than twice and a half the 

 height ; valves rather convex ; anterior or longer side regularly 

 rounded ; posterior extremity more narrowly rounded ; basal 

 margin nearly or quite straight along the central region, but 

 rounding np at the extremities, the curve being more gradual 

 behind ; beaks depressed to a level with the dorsal margin, and 

 placed somewhat behind the middle; dorsal margin a little con- 

 vex and nearly horizontal in front of the beaks, but rounding 

 regularly into the anterior outline, and behind the beaks, slighth* 

 depresscd below the horizon of the latter, though without sloping- 

 much posteriorly. Surface apparently smooth ; interior showing 

 distinct radiating strise below the middle of the valves, excepting 

 near the extremities. Posterior muscular impression rather nar- 

 row, suboval, oblique, placed near the margin, and well defined 

 by a slight oblique ridge along its antero-inferior margin ; anterior 

 do. larger and faintly marked. 



Length, 1.22 inches; height, 0.50 inch; convexity, about 0.32 

 inch. 



This is another tj'pe very nnexpectedly found among the Cor- 

 niferous siDeciraens. So far as I am aware, no example of this 

 group has ever before been obtained from an^^ horizon below the 

 mountain limestone. Whether we regard the Carboniferous and 

 Permian forms usuall}^ referred to Solenomya, as really belonging 

 to that genus, or as constituting a distinct group (for which Prof. 

 King proposed the name Janeia), there can be no question what- 

 ever, that the shell here described belongs to the genus that in- 

 cludes these Carboniferous and Permian species. Specifically, it is 

 perhaps more nearly related to S. biarmica of the European Per- 

 mian rocks, than it is to S. Puzosiana, de Kon., or to P. primaeva, 



[June 6, 

 / 



