

Remarks . - The members of this v/ell-re presented variety are 

 sharply differentiated from the oo-existent ledas. The eloiHrate, 

 equilateral form, polished surface and ventral orowdiix?: of the 

 fine riiffae are characteristio features. Then compared with the 

 more ahundant and highly variable pelt el la and indisrena the char- 

 acters of the variety under discussion are constant. There is, 

 however, a slight vsriation in shape, a few of the valves be ins- 

 higher and therefore less elongate than the typical form; this 

 difference in outline is fre-uently encountered among immature 

 forms. The extreme elongated variants of peltella somewhat res- 

 emble subvitreamorpha , but the tv^'o may sa readily be distinguish- 

 ed since subvitreamorpha is less inequilateral, more convex, more 

 bluntly rostrate and has more tumid and more decidedly opistho- 

 gyrate umbones and distally crowded mgae; moreover, it does not 

 have the lujaule or sharp posterior carina of cerata . 



In the rational l.luseum collection of Bowden material this 

 form bears the naiae leda v itrea d'Orbigny, although that species 

 does not appear in the 1903 check-list. ■ 1) A-jparently there is 

 some confusion concerning I. vitrea d'Orbigny (2) and at the 



(1). Trans. Jagne r ^ree Inst. 3ci., Philadelphia, vol. 3, pt. 6, 

 n. 1=^86. Several Ledas which do not appear in any of the 

 Bowden collections at the writer's disposal are included 

 in this list. 



(2). In de la Sagra, Hist., Phys., polit. et natur. riQ I'isle 

 de Cuba, "oilusques, vol. 2, pp. 262-255, pi. 26, fisrs. 

 27-29, 1855 (drench ed.-) 



