- 215 - 



left valve is about ss much inflated as the rin-ht it is r' ri'TM.e'ilj/ 

 differeiit from the left valve of the Bov/den form. i'he roce.it P. 

 !:iayapi;sensis Dall and Simpson (1) closely resemhles the yoii-ig of 



(1). Bull. U. S. ?ish Comm., vol. 20, -ot. 1, ■). 4o5, pi. 55, figs, 

 V-T, 1901. 



aoutiniot^is in outline and sculpture, hut the rihs are lov;er and 

 not quite as soiiare. 



It was surpris in?^ to discover that the Santo ;Ooraii\!?ian form 

 differs from the inaecualis from 3ov;den and other Antillean loc- 

 alities. Apparently the 1 -r-.-^-ftS'^^-^hl i nhfMl oorioe-ot '^f inaec^imli s 

 was hased on Guppy's figure, v/nich, it m^.st be remembered, repres- 

 ents a Jamaican, nreseumahly 3o"'den, foim, and on Cur ' jpeeimens, 

 In the case of this species, as with Sowerhy'vS otn.-^r -m-^-' -"^iired spe- 

 cies, it is assiuned that (?abb's Santo Domins-ian foi-ms are the same 

 as those v/hich Sowerhy described imless they obviously ~' ""^r from 

 Sowerby's diagnosis, altT- -^--^-h '-h^t ascumption may be incorrect; at 

 least, it seems advisable to liiiit Sowerby's names to Santo Domin- 

 gian forms v/henevor closely related, but different, species occur 

 elsewhere. ' The typical inaecualis, -^s h.ere restricted, reaches a 

 larger sise than its Bowden variety and although left valves are 

 virtiaal"'-y identical in a-roearance, the rib'o of rir-ht valves are 

 lower, more rounder^, v.l thout the flat tops liiid e.:c'-'avate '. flanl-rs 



