•2V.) 

 Gems GOSSELETTIA. Bakrois. 



[Ety. : Proper name.] 

 (1881: Ann. Soc. Geol. du Nord, Vol. VIII.. p. 176.] 



Shell sub-triaiigiila r, truncate on the anterior side, sub-alate 

 on the posterior side. Liganiental area \Yide. lontiitndinally 

 striate. Cardinal teeth strong, situated under the beak. 

 Lateral teeth elongate. Surface marked by concentric stria-. 



GossELETTi.\ RETUSA. Hall. (Fig. 164.) (Pal. N. Y., 

 Vol. v., Pt. I., ]). 266, PI. XXXIII.) 



Distinguishing Cliaracters. — Oblique rhonilioidal outline; 

 ''anterior margin nearly straight for two-thirds of the 

 length, inflated at the byssal opening, and concave below.'' 



Fig. 164. Gosselettia retusa. Left and autero-eardinal view of the type specimen, from 

 Eighteen Mile Creek (from Hall). 



Found ''in the Hamilton grouji, at Eighteen Mile Creek, 

 Erie County, X. Y." (Hall, type.) 



Gexus MODIOMORPHA. Hall. 



[Ety. : Modiola, a genus ; morphe, form.] 

 (1870 : Preliminary Notice LamellibrancLiata, 2, p. 72.) 



Shells with equal but very inequilateral valves, which are 

 sub-ovate in outline, largest posteriorly, and with a i-ounded, 

 projecting anterior end. A depression, or "cincture," pasvses 



