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 narrowly 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, form- 

 ing an angle of about 70 degrees with the posterior extremity; posterior 

 margin straight below, sharply truncated above, forming an angle 

 of 155 degrees with the hinge line; a prominent umbonal ridge ex- 

 tending obliquely backward from the beak to the posterior inferior 

 angle. Surface smooth except for a few faint concentric lines of 

 growth near the margins. 



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 

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

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

 Solenomorpha solenoides (Geinitz) in which species the shell tapers 

 posteriorly becoming bluntly pointed at the posterior extremity. 

 The shell is extremely thin and fragile, although with care specimens 

 in good condition can be obtained. 



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

 (Locality 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 fossils from the Pottsville rocks of Stark and Mahoning counties 

 were made. 



Genus Edmondia DeKoninck 

 Edmondia ? peroblonga Meek and Worthen? 



1865 Edmondia ? peroblenga. Meek and Worthen, Proc. Acad. Nat. Sci. Phil, 



p. 249. 



Upper Coal Measures: Lasalle, Illinois. 

 1873 Edmondia ? peroblonga. Meek and Worthen, Geol. Surv. 111., Vol. 5, p. 583, 



PI. 27, Fig. 4. 



Upper Coal Measures: Lasalle, Illinois. 



A form closely related to E. peroblonga occurs in the Boggs lime- 

 stone of Muskingum County, which is represented by a single specimen 

 somewhat imperfect at the posterior extremity. The size is about 

 two-thirds that of the specimen described and figured by Meek and 

 Worthen, and the resemblance between the two forms is so close, 

 that if they do not represent the same species, they at least show a 

 very close relationship. They are probably not identical, as E. ? 



