42 ZOOLOGICAL COLLECTIONS MADE DURING [Jan. 4, 



dirty whitish, marked with irregular, concentric, subtrauslucid 

 zones ; impressions shallow, the anterior rather narrower than the 

 posterior ; above the former is a second separate minute subcircular 

 pit and a similar one joining the upper margin of the latter. Basal 

 margin of valves minutely dentate within. Teeth of right valve two : 

 the anterior, or that nearest the side towards which the beak 

 curves, very small, conical ; the other elongate, bifid. In the other 

 valve two teeth also, the anterior bifid, stouter and shorter than the 

 posterior, which is simple. Anterior dorsal margin of right valve and 

 posterior of the left grooved to receive a thin corresponding 

 elongate lamella on the opposite margins of the respective valves. 

 Length 5 miUims., width 4-^, diameter 2. 



Hab. Boija Bay, Straits" of Magellan, 20 fathoms, on a bottom 

 composed of stones and dead shells. 



The discovery of this species in antarctic latitudes is especially 

 interesting, being another instance of the occurrence of a genus in 

 antarctic regions which is peculiarly boreal in its distribution. 

 A. longirostra, d'Orbigny, from the Falkland Islands, is allied to 

 this species. It is, however, more beaked, much more finely 

 sculptured, and has a smooth margin to the valves. 



Cardita (Actinobolus) velutinus, sp. n. (Plate V. fig. S.) 

 Shell equivalve, rather inequilateral, globose, as long as broad, 

 whitish, clothed with a thickish velvety pilose dirty brownish 

 epidermis, sculptured with about twenty elevated rounded and some- 

 what granulous costEe, which are furthest apart anteriorly, and 

 more approxitnated on the hinder slope of the valves ; the inter- 

 stices are about as broad as the ribs. Umbones prominent, much 

 incurved. Lunule very deep, shortly cordiform. Central tooth in 

 rio-ht valve very strong, triangular, striated at the sides. Left valve 

 with a deep central triangular pit, which receives the tooth of the 

 other valve, and a tooth on each side, whereof the anterior is small, 

 rather acute and prominent, and the other elongate, thin, striated on 

 the outer side. Anterior scar elongate, twice as long as broad, 

 posterior much shorter. Margin of the valves dentate within. 

 Interior bluish white near the margin, and feebly tinted with yellow 

 or rose in the concavity. Width 19 miUims., length 19, thick- 

 ness I4|. 



Hah~ Station 2; and Wolsey anchorage, 17 fathoms. 



C. spurca, Sowerby, is the nearest ally of this species. It is, 

 however, of a longer and squarer form ; and the epidermis is different. 



Cardita (Actinobolus) compressus, Reeve. 

 Hab. Station 5, and Boija Bay, 20 fms., on a stony and shelly 

 bottom. Valparaiso {Reeve). 



Carditella, n. g. 



Shell exteriorly like Cardita. Hinge composed of two cardinal 

 teeth in the left valve and one in the other. Each valve also has two 

 lateral teeth, one nearly marginal on the one side, the other on the 



