328 ANTILLEAN FOSSILS— GUPPY AND BALL. vol. xix. 



apparently complete, siplioiial end slightly gaping, truncate, the mar- 

 gins thickened and reflected, the dorsal plates wanting, probably lost. 

 Alt., G mm. 



Oligoceneof Jamaica, A^endryes ((Uippy, 2l>J)()). Ko. 107100, U.S.X.M. 

 This very singular little pholad is unfortunately imperfect, rendering- 

 it advisable to await more material before describing it. It was received 

 with the mauuscrii)t name of Martcsia spJuvroidalis, but it is not a 

 Martesia and jierhaps may prove a Teredinn. 



DIMYA GRANDIS, Dall, new species. 



Shell large for the geuus, ostreiform, attached by the right valve; 

 externally smooth or (in the variety cUvaricata) rather strongly sculj)- 

 tured with close-set dichotomous radiating ribs; interiuilly smooth and 

 nacreous near the edges; the visceral area with a porcellanous, finely 

 granulated coat, posterior adductor leaving a duijlex scar, as in 1>. 

 (irgentca, Dall; anterior scar single, small, close to the pallial border 

 and high up in the valve; pallial area bordered" by a line of minute, 

 fringe-like, short grooves; cardinal crura raised on each side of the 

 small, subtriaugular socket for the resilium, behind which they Join, 

 forming in the right valve a keystone-shaped projection which fits 

 inside the pair on the left valve. Alt. 32, lat. .'50 mm. 



Oligoceue of the Potrero, Eio Amina, Santo Domingo, Bland. Xo. 

 113799, U.S.N.M. 



The genus Dimt/odon, Munier Chalmas, is characterized chiefly by its 

 undivided ijosterior adductor scar, the tooth-like crura being present 

 though feeble in the typical IHmya. The present form has the scars of 

 JJimya and well-develoi)ed crura. From the recent I>. avf/entea it is 

 distinguished by sculpture, size, and hinge. 



The differences of sculpture do not appear to be due to the object 

 upon which the shell attaches itself, as tiiis attachment is only by a 

 very small portion of the surface. 



Mr. (lupi)y's Avork was done largely without the advantages of books 

 and specimens for reference, hence it naturally followed that his names 

 in some cases require revision. With his types for comparison I have 

 been able to correct some of these misidentifications, and the present 

 0('casion seems a proper one for putting the corrections on record, with 

 notes on some other species : 



ColumhelJa amhigna and C. firadata, Gup])y, are referable to the genus 

 Stromhina. 



ColmnhcUa pemdiaris^ Cruppy, is an ^J^sopus, nearlj^ related to A-iJ. 

 sfearnsii, Tryon. 



^fala{AcriUa) leroj/i, Guppy, has also been collected on the Isthmus, 

 near Gatun. 



Clea tnincataj Guppy, is a rianaxis which Mr. Guppy wrongly iden- 

 tified with EtracheUza tnmcata, Gabb. Although ]Mr. Guppy ^ figures 

 the genuine shell, his specimens are quite different. 



' Jonrn. (Jeol. 8oc., XXXII. pi. xxix, fig. 6. 



