24 Melvill, Descriptions of Marine Mollusca. 



DONAX APERITTUS, Sp. 110V. (PL J, f. 33). 



D. testa solidiuscula, compacta, Icevi, nitida, indistincte 

 lirata, latere antico producto, postico subtruncato, paidlum 

 extenso, radiatim recti-corrugato, margine ventrali minute 

 serrato, umbonibus inconspicuis, planatis. 



Long. 8, lat. 15 mm. 



Hab. Karachi. 



A smooth shell, with the anterior side produced, some- 

 what truncate, though slightly extended also posteriorly, 

 the radiate corrugations being prominent ; the rest of 

 the surface almost smooth, the umbones inconspicuous ; 

 ventral margin minutely serrate. 



(a7r€piTT0<?, simple.) 



Pectunculus maskatensis, sp. nov. (PI. 7, f. 32). 



P. testa paidlum compressa, cequilaterali, solidiuscula, 

 rotundata, dorsaliter recta, brunneo-rufo-alboque sparsa, um- 

 bonibus parvis sed conspicuis, radiatini fortiter costidata, costis 

 uniformibus, apud medium et infra sidculo divisis, utrdque 

 parte nodidis parvis decoratis, interstitiis spiraliter tenuissime 

 liratis, cardine dentibus octodecim in utrdqite valvd instmcto, 

 pidclire brunneo-tinctis, interiore albo-lacteo. 



Alt. 22, lat. 25, diam. 10 mm. 



Hab. Muscat (or Maskat), Arabia, 10 fathoms in sandy 

 mud. 



Allied to the well-known P. pectiniformis, Lam., but 

 the ribs, as seen by the above description, are of an 

 entirely different character, being smooth and undivided 

 by a sulculus in Lamarck's species. It ranks among the 

 more select of a genus famous for a highly-individualised 

 type of beauty. 



