DESCRIPTION OF SPECIES 195 



Genus Solenomorpha Cockerell 



Solenomorpha lamborni n. sp. 

 PI. X, fig. 3 



Description. Shell small, elongate, length about four times the 

 height; convex, with maximum convexity in the anterior half of the 

 shell behind the beak; beak small, inconspicuous, depressed, directed 

 anteriorly, scarcely distinct from the cardinal margin, situated about 

 one-eighth the length of the shell from the anterior margin, separated 

 from the anterior portion by a short, oblique groove; cardinal margin 

 long, straight, extending posteriorly from the beak two-thirds the 

 length of the shell; anterior margin broadly rounded dorsally, but nar- 

 rowly rounded or slightly truncated ventrally, joining the ventral 

 margin at a point one-third the length of the shell from the anterior 

 end; ventral margin straight, parallel to the hinge line, forming an 

 angle of about 80 degrees with the posterior extremity; posterior margin 

 straight below, sharply truncated above, forming an angle of 155 dp- 

 grees with the hinge line; a prominent umbonal ridge extending ob- 

 liquely backward from the beak to the posterior inferior angle. Surface 

 smooth except for a few faint concentric lines of growth near the mar- 

 gins. 



Dimensions. The holotype measures: length 22 mm., length of 

 hinge line 13 mm., height 5.5 mm., convexity of right valve 1.5 mm. 



Remarks. This species has been found only as internal casts 

 from the Sharon ore of a single locality in Scioto County, where it is 

 of comparatively common occurrence. It is characterized by its elon- 

 gate form, its small, inconspicuous, depressed beak, and its parallel 

 dorsal and ventral margins. In the latter respect it differs from Sol- 

 enomorpha solenoides (Geinitz), a species which has the shell tapering 

 posteriorly and becoming bluntly pointed at the posterior extremity. 

 The form is extremely fragile, although with care specimens in good 

 condition can be obtained. 



Horizon and locality. Sharon ore: Lick Run, Scioto County, Lo- 

 cality 2, c. The specific name is given in honor of Mr. Raymond E. 

 Lamborn of the Geological Survey of Ohio, by whom the collections of 

 Pottsville fossils from Stark and Mahoning counties were made. 



Genus Prothyris Meek 



Prothyris elegans Meek 

 PI. XIV, fig. 12 



1871 Prothyris elegans. Meek, Am. Jour. Conch., Vol. 7, p. 8, PI. 1, Fig. 3. 

 Coal Measures: Nebraska City, Nebraska; Ohio; Illinois; Michigan. 



