304 MR. E. A. SMITH ON THE [Apr. 1 , 



are therefore compelled to designate it Basterotin, the name given 

 by Homes, who appears to have been ignorant of the fact that, not 

 only Gray, but Recluz also, had previously recognized the existence 

 of this generic group. 



Las^a adansoniana (Recluz). 



Poronia adansoniana, Recluz, Rev. Zool. 184.3, p. 174; id. in 

 Chenu's Illus. Conchyl. pi. i. figs. 1 a-g. 

 Hub. Senegal. 



LuciNA iNCONSPicuA. (Plate XXII. fig. 6.) 



Testa minima, altior quam longa, mediocriter convexa, inaqui- 

 lateralis, soUdiuscula, alhida, concentrice regulariter tenuiter 

 striata, striisque radiantibus vix conspicuis sculpta ; mnbones 

 acuti, antrorsum curvati; lunula profunda, parva ; margo 

 dorsi posticus leviter excurvatus ; pagina interna nitida, 

 ad marginem minute denticulata ; denies cardinales et laterules 

 validi. 

 Longit. 3 millim., alt. 3g, diam. 2. 



This species, although so small, is conspicuously solid. The um- 

 bones are well curved forward, producing a beaked appearance to the 

 apex. The radiating striae are excessively fine and only visible in 

 certain lights, and seem to be lines below the surface. 



LxjciNA (Codakia) compacta. (Plate XXII. fig. 7.) 



Testa tequila teralis, mediocriter globosa, alba vel dilute citrina, 

 concentrice et radiutim tenuissime et confertim lirata, minute 

 cancellata ; umbones leviter prominentes ; lunula angusta, parva, 

 mediocriter profunda ; latus posticum obtusum, anticum rotun- 

 datum ; margo inferior intus striatus, subcrenulatus ; ligamen- 

 tum internum. 

 Longit. 10 millim.., alt. 9|, diam, 6. 



The dentition and the muscular impressions of this species are 

 nornjal. The sculpture is so fine that it is almost invisible to the 

 naked eye. Specimens were collected l)oth by Capt. Turton and 

 Mr. Melliss. It appears to be a common species. 



Verticordia ornata (d'Orbigny). 



The three odd valves from St. Helena agree precisely with those 

 described in my Report on the Lamellibranchiata of the ' Challenger ' 

 Expedition, p. 166. The synonymy and distribution of this species 

 are there given. St. Helena is the most southern known locahty. 



Mytilus exustus, Linn. 



Mytilus exustus. Reeve, Conch. Icon. fig. 10 ; Clessin, Conch .- 

 Cab. ed. 2, p!. 16. figs. 7, 8. 



Hab. West Indies, Brazil, U. States as far north as Charleston. 



A few small odd valves, received in 1865 from the Museum of 

 Economic Geology, apparently belong to this species. 



