198 



valves are closed, is flat, with angular crenated edges. It was 

 dredged in sandy mud, at a depth of nine fathoms. — G. B. S. 



NucuLA POLITA. Nuc. tcstd ohlofigd, antice rostratd, albd, epi- 

 dermide vircscente, politd ; margine dorsali anticd Icevi ; striis 

 iionnullis obliquis anticis : long. ] •4', alt. 0'6, led. 0'A5 poll. 



Hab. ad Panamani. 



A single^specimen of this very beautiful species was dredged up 

 in sand from a depth of seven fathoms. — G. B. S. 



NucuLA PisuM. Nuc. tcsid parvu, oblique ovali, latere antico 

 brevissimo, margine dorsallinclinntd : long.0'25, lat.O'lS) alt. 

 0-2 poll. 

 Hab. ad Valparaiso. 



Dredged in coarse sand and gravel, at various depths from seven 

 to forty fathoms. — G. B. S. 



NucuLA coSTELi-ATA. Nuc. tcstd oblongd, tenui, antic'^ ros- 

 tratd, acuminatdt costis duabus dorsalibus approximatis, crenu- 

 laiis ; costeUis acutis co7icentricis, totam superficiem tegentibus : 

 long. 0-8, alt. OS, lat. 0-2 poll. 



Hab. ad Panamam. 



Two specimens were taken in sandy mud at a depth of ten fa- 

 thoms. A thin epidermis covers the shell. — G. B. S. 



NucuLA GiBBOSA. Nuc. testd oblo?iga, gibbosd, antice acumiiiatO' 

 rostratd) longitudinaliter sulcatd ; dorso antico depresso, inargi- 

 nibus centralibns elevatis : long. 1*2, lat. 0'55, alt. 0'6 2^011. 

 Hab. ad littora Peruviae. 



Found in soft mud, at a depth of five fathoms, at Tumbez in Peru. 

 A variety, with a less elevated ridge in the centre of the anterior 

 dorsal margin, and of much smaller size, was found in mud, at 

 twelve fathoms, in the Gulf of Nocoiyo. — G. B. S. 



NucuLA Elenensis. Nuc. testd ovatd, gibbosd, longittidinaliter 

 stdcatd, antice rostrato-acuminatd ; limbo dorsali antico arcuato, 

 marginibus crenulatis : long. 0*5, lat. 0*25, alt. 0*35 poll. 



Hab. ad Sanctam Elenam. 



Dredged in sandy mud at a depth of six fathoms. — G. B. S. 



NucuLA EBURNEA. Nuc. tcstd ovutu , gibbosd, longitudinaliter 

 sulcatd, nitidd, eburned, antice rostralo-acuminatd : long.0'65, 

 lat. OS, alt. 0-35 poll. 

 Hab. ad oras Columbise Occidentalis. 



Found in sandy mud, at a depth of from seven to nine fathoms, 

 in the Bay of Caraccas. — G. B. S. 



NucuLA cuNEATA. Nuc. testd ovato.cunetformi, gibbosd, epider- 

 midc virescente, nitidd, latere postico rotundato, antico acuminato ; 

 superficie concentrice sulcatd : long. 0*4, lat. 2, alt. 0*25 poll. 



Hab. ad Valparaiso. 



Dredged in coarse sand and gravel, at various depths, from four- 

 teen to forty-five fathoms. — G. B. S. 



NucuLA ExiGUA. Nuc. testd parvd, oblique ovatd, albicanie, pel- 



