32 THE VOYAGE OF H.M.S. CHALLENGER. 



Corhula scaphoides, Hinds (PI. Ylll. figs. 3-3Z>). 



Curhida scapJtoiden, IliiiJs, Proc. Zool. Soc. LoniL, 184.3, p. 5G. 

 Ciirhula scaphoides, Reeve, Concli. loon., vol. ii. tig. 2-t. 



Habitat — Torres Strait, in 3 to 1 1 fathoms (Challenger) ; Singapore and Philippine 

 Islands (Hinds), Hong Kong Harbour (Bowring). 



The specimens described by Hinds were apparently only the young of this species, 

 judging from a single right valve obtained by the Challenger. This valve bears a 

 considerable resemblance to the dee]) one of Corhula tunicata or Corhula sulcata, but 

 is much broader at the upper part, tlie young shell being much more elongate in this 

 species than in either of those mentioned. It is 25 mm. long, 17 high, and as 

 deep as that of Corhula tunicata. The young shell, about 13 mm. in length, forms 

 as it were an umbonal cap as in many species of this genus. From this point the 

 concentric ridges gradually thicken, and are more or less undulating. They are 

 attenuated anteriorly, and become more slender and closely packed at the carina, which 

 runs from the beak to the posterior extremity, which is much narrowed, and has a 

 pinched or nasute appearance. In young shells the surface is also ornamented with 

 numerous excessively fine radiating granular lirse, which are not, however, traceable in 

 the single adult valve, as the surface is too much worn. The hinder muscular scar is 

 situated on a shelf-like projection, this feature being also noticeable in the young shells. 



In the British Museum there is a single adult specimen of this species from Hong- 

 Kong Harbour, presented by J. C. Bowi'ing, Esq. This is in perfect condition, but not 

 quite as large as the Challenger valve. There certainly is a very close relationship 

 between this species and Corhula tunicata, the main distinction consisting in the much 

 longer umbonal portion of the valves in the present form. Both have exactly the same 

 kind of radiating series of minute circular granules, the epidermis covering the lower half 

 of the left valve is similar in both forms, and the muscular impressions are not very 

 dissinailar, although in Corhula scaphoides the posterior stands out rather more than 

 that of Corhula tunicata. Both have exactly the same stout, curved, and acute 

 cardinal tooth in the deep valve, and their external ribbing is also similar. 



Corhula modesta, Hinds. 



Corhida modesta, Hinds, Proc. Zool. Soc. Lond., 1843, p. .57. 

 Corhida modesta, Reeve, Concli. Icon., vol. ii. fig. 14. 

 Corhvla modesta. Smith, Proc. Zool. Soc. Lond., 1871, p. 728. 



Hahitat. — Amboina, in 15 to 20 fathoms; also Station 172, off Nukalofa, Tongatabu, 

 in 18 fathoms (Challenger); Philippine Islands and Malacca (Hinds); ^^^lydah, West 

 Africa (Knocker). 



