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Subgenus Orassinella Guppy. 



GRASS ATELIITE3 ( GRilSSIKELLA) GUPPYI Hall. 



Grasslnclla I'lsrtiniQensis Gmip-:, 1874, ^-eol. Hag. deeacle 2, vol, 

 1, p. 442, (oheok list), ex ;:Erte, non d ' Orb i p/ny , 1845. 



Grassatellltes (Grassinella) Gup-pyi Dall , in Gtip-,-)y and Dall, 1896, 

 Proo. U. '3. I'at. Hub., vol. 19, p. 32 5, pi. f.O, fig. 5. 



Grassatellites ( Grassinella ) Guppyi Dall, 1903, 'Trans. V/agner ?ree 

 Inst. 3ei., Philadelphia, vol* 3, pt. 6, p. 1476. 



Sesoripti jn .- "Hounded trigonal, flattish, concentrically 

 costate, v.lth 10 to 12 lamellar ribs, much narrower than the in-, 

 terstices. 'T-. 4.5, Ion. 1-.6 rn." (Dall, 1896). 



Tyoe locality .- Jamaica. 



Shell small, compressed or slightly inflated, outline irreg- 

 ularly rounde-^ -triangular, moderately iziequilateral; posterior 

 dorsal margin usually slightly longer than the anterior and sli=rht- 

 ly e::Gavate', esrie daily ■:; ri o-ht valve, meeting the ventral 



margin at a sharp or subrounded angle; aiiterior dorsal margin 

 straighter or slightly conve::, riutiding into the usually asymmet- 

 ricelly arcuate base; lunbones relatively high, apically acute and 

 compressed, slightly opisthogyrate ; escutcheon usually --^vider and 

 more de^-ply i--pressed than the lunule; external surface of the 

 ariult valve sculptured vath eight to sixteen sharp concentric lam- 



