REPORT ON THE LAMELLIBRANCHIATA. 159 



culated ribs. These are very much broader than the intervening grooves, and of different 

 %vidths, the widest being dov\Ti the anterior side, and the narrowest at the opposite end. 

 The tubercles upon them are closely packed and compressed, or, in other words, 

 transversely elongated, a feature especially observable upon the stoutest ribs. The 

 beaks are moderately prominent, well tui-ned over towards the front, and decidedly 

 antemedian. The dorsal margin descends very suddenly in a slight curve in front, but 

 rises somewhat in a straightish line behind the beaks. The anterior end is broadly 

 arcuate, gently rounding into the ventral margin, which is also widely curved. The 

 hinder extremity has a tendency to oblique truncation, although the l^oundary is in 

 reality on a gentle curve. It joins the dorsal margin in a rounded angle having a high- 

 shouldered appearance, the result of the rising of the dorsal line. The interior is white, 

 radiately narrowlj^ grooved and rather strongly dentate along the margin. 



Length 7 mm., height 7, diameter 5. 



Habitat. — Off Levuka, Fiji Islands, in 12 fathoms (Challenger) ; Gulf of Suez (Issel 

 and MacAndrew). 



This very pretty little shell, which probably attains a larger size, is chiefly 

 characterised by its form and the closely packed transverse tubercles upon the ridges. 

 Having carefully compared specimens from Fiji with examples from the Gulf of Suez, 

 I am unable to discover any distinctions except that in the former there is an absence 

 of coloiu', due probably to their dead condition. 



Cardium (Bucardium) mirahile, Deshayes (PL VIII. figs. 1— Ic). 



Cardium mirahile, Deshayes, Proc. ZooL Soc. Lond., 1854, p. 332. 

 Habitat. — Station 203, PhOippine Islands, in 12 to 20 fathoms ; mud. 



This beautiful species bears some resemljlance to Cardium asiaticum^ but has fewer 

 and stouter ribs, has not the posterior prominence of that species, and is remarkable on 

 account of the short white spines upon the costas. 



Cardium (Bucardium) tenuicostatum, Lamarck. 



Cardium tenuicostatum, Lamarck, Aniru. sans vert, ed. 2, vol. vi. p. 392. 



Cardium tenuicostatum, Delessert, Eecueil, pL xi. figs. 6, a^c. 



Cardium tenuicostatum, Sowerby, Conch. 111., figs. 36, 62. 



Cardium tenuicostatum. Reeve, Conch. Icon., vol. ii. fig. 50. 



Cardium tenuicostatum, Romer, Conch.-Cab., ed. 2, p. 69, pL xii. figs. 6, 7. 



Cardium pallidum, Romer, loc. cit., fig. 92. 



Cardium radiutum, Edmer, loc. cit., fig. 89. 



Habitat. — Port Jackson, Sydney, in 2 to 10 fothoms ; also Station 208, Philippine 

 Islands, in 18 fathoms. 



