197 



ventrali antico rotundato, postico leviter fiexuoso ; umbonihus ni- 

 gricanti-purpurascentibus : long. 33, alt. 2*3, lat. 1*35 poll, 

 Hab. in Peruvia et America Centrali. 



Dredged among coarse gravel, in twelve fathoms water, in the 

 Gulf of Nocoiyo. A smaller variety, which is also rather higher, 

 was found at Tumbez, at a depth of five fathoms, in thin mud. — 

 G. B. S. 



Genus Solenella, G. Sowerby. fr J 



Testa ovalis, cequivalvis, subcequilateralis, compressa, nitens, epi- 

 dermide olivaceo-viridi, tenui, induta ; dentibus cardinalibus 

 nullis, later alibus anticis in utrdque valvd, tribus ad quaiuor, 

 lateralibus posticis plurimis, seriem rectiusculam effbrmarttibus, 

 omnibus parvis acutis ; impressionibus muscularibus duabus, la- 

 teralibus, subdistantibus ; impressione pallii sinu magno : liga- 

 mento externo, elongato. 

 An interesting new genus of marine*bivalves, in which the general 

 form and characters of M. Blainville's Solenocurtus are combined 

 with the series of minute sharp teeth characteristic of Nucula. . It 

 appears to belong to the family of the Solenacece, and it may at 

 once be separated from the Mactracece, to which Nucula belongs, 

 by the circumstance of the whole of the ligament being external. 



Solenella Norrisii. Sol. testd albido-ccerulescente ; epidermide 

 olivaceo-mridiy zonis concentricis saturatioribus : long. 1*6, alt. I, 

 lat. 04 poll. 



Hab. ad Valparaiso. 



Discovered by Mr. Cuming, in soft mud, at from fourteen to 

 forty-five fathoms depth. 



This is the only species of the genus I have seen ; but Mr. Cuming 

 informs me that he obtained a single valve of another and very dif- 

 ferent species. By the specific name I wish to honour and keep in 

 remembrance Thomas Norris, Esq., of Redvales, near Bury, 

 Lancashire. — G. B. S. 



Genus Nucula. 



Nucula elongata. Nuc. testd elongatd, lanceolatd, tenui , albd, 

 epidermide fused prope marginem ventralem indutd ; subcequi- 

 laterali, latere antico breviore ; margine dorsuli rectiusculd, pos- 

 tice subreflexd; serie dentium posticd divaricatd : long. 2*7, lat. 

 0-25, alt. 0-7. 



Hab. in Columbia Occidentali. 



Dredged in sandy mud, at a depth of twelve fathoms, at Xipi- 

 xapi. 



Nucula crenifera. Nuc. testd elongatd, lanceolatd, Icevigatd, 

 tenuissime longitudinaliter striata ',; marginibus dorsalibus cari- 

 natis, carinis concinne crenulatis: long. 1*4, alt. 0'4, lat. 0*2 poll. 



Hab. ad Xipixapi. 



This species approaches nearly in shape to Nuc.lanceolata ; it is, 

 however, broader and higher, and its dorsal margin, when the two 



