308 Zoological Society. 



NevEra costata, Sow. (s}).) 



Anatina costata, Sowerby, Proc. Zool. Soc. 1834, p. 87. 



Hab. The west coast of America, between 2° 47' and 8° 5' north 

 lat., namely at St. Helena, from six fathoms, sandy mud ; Magnetic 

 Island, twenty-two fathoms; and coastofVeragua, twenty-six fathoms, 

 mud. Cab. Belcher et Cuming. 



Ne^ra Gouldiana. N. testd oblongd,fragili, hyalind, ventricosd ; 

 costis duodecim radiantibus ; valvis valde incegualibus ; rostro 

 lineis tribus obliquis elevatis. Long. 3-1- ; lat. 1| ; alt. 2 lin. 



Hab. New Guinea ; Cagayan, island of Mindanao ; and Bay of 

 Manila, PhiHppines : in from seven to thirty fathoms, sandy mud. 



Cab. Cuming et Belcher, 



The specific name is in honour of Dr. Gould, the author of the 

 able and luminous Report on the Moilusca of Massachusetts. 



Ne^ra Singaporensis. N. testd oblongd,fragili, hyalind, ventri- 

 cosd, costis 17-20 radiantibus; valvis incegualibus ; rostro bre- 

 viusculo, lineis tribus obliquis elevatis. Long. 2^; lat. 1^; alt. 

 If lin. 

 Hab. Singapore ; in seven fathoms, mud. 

 Cab. Cuming. A single specimen. 



A shell so very similar to N. Gouldiana that it might most easily 

 be confounded with it. In that species however I find the number 

 of radiating ribs to be so constant in a number of individuals, that I 

 must regard it a good diagnostic character. The present species then 

 will be found to differ from it in its smaller size, diminished number 

 of radiating ribs, and shorter beak. 



Ne^ra casta. N. testd oblongd,fragili, hyalind, ventricosd ; costis 



numerosis radiantibus, minoribus alternantibus, transverse subtilis- 



sime striatd ; rostro breviusculo, parvo, lineis obliquis elevatis in- 



structo. Long. 2^ ; lat. 1^ ; alt. 1^ lin. 



Hab. New Guinea ; dredged from a muddy floor in seven fathoms. 



Cab. Belcher. 



Ne^ra concinna. N. testd oblongd, fragili, subplanulatd ; costis 

 numerosis, parvis, confertis, ultimd maximd ; valvis subcEqualibus ; 

 rostro parvo, breviusculo, lineis tribus obliquis elevatis instructo. 

 Long. 2^ ; lat. 1 ; alt. 1-i lin. 



Hab. ? Cab. Cuming. 



Nejera didyma. N. testd oblongd, Icevigatd, albd ; costis duabus 

 radiantibus ; margine dorsali antico prominulo ; rostro lato, sub- 

 truncato. Long. 3 ; lat. 2 ; alt. 2 lin. 

 Hab. The west coast of Veragua, in twenty-six fathoms, mud ; in 

 society with N. costata. 

 Cab. Belcher. 



On the anterior and ventral margin there is a disposition to the 

 formation of a number of small ribs ; the shell is otherwise smooth 

 and left to the occupation of the two prominent ribs, which eminently 

 distinguish it. 



Ne^ra rosea. N. testd oblongd, albidd, epidermide tenui striatd 

 indutd; valvis incequalibus , dextrdmajori ; rostro attenuato, rosea. 

 Long. 31; lat. If; alt. 2 lin. 



