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



the margin is a sign of maturity. As d'Orbigny's typical specimens in the British 

 Museum are hirger than any as yet known of Astarte magellanica, and have smooth 

 margins to the valves, it seems likely that that species has not wrinkled edges. This, 

 however, is uncertain, as the adult shell possiljly has yet to be discovered. 



Subfamily Carditin.e. 



Cardita, Brugiere. 

 Cardita calyculata (Linu^). 



Cardita calyculata, Lamarck, Aniin. sans vert., vol. vi. p. 24. 

 Cardita calycidata, Philippi, Enum. Moll. Sicil, vol. i. p. 55. 

 Cardita muricata, Sowerby, Proc. Zool. Soc. Lond., 1832, p. 195. 

 Cardita muricata, Reeve, Conch. Icon., vol. i. pi. iv. fig. 18, var. 



Habitat. — -Station 162, oif East Moncoeur Island, Bass Strait, in 38 to 40 fathoms, 

 and off Tenerife, in 70 fathoms. 



After a careful comparison of the few small valves from Bass Strait, with sjjecimens 

 of the same size from the coast of Piedmont, I am unable to detect any good and sufficient 

 reasons for separating them specifically. The number of cost» is the same, but a few of 

 them upon the anterior half of the valves may perhaps be slightly coarser in the shells 

 under examination than in those from the Mediterranean, and the anteiior end in the 

 latter does perhaps project forward rather further beyond the umbones than in Australian 

 shells. The hinge, however, is absolutely identical in both. 



Cardita muricata of Sowerby, said to have been found at Crescent and Eapa Islands, 

 and of which there is a specimen in the British Museum from Nairai, Fiji Islands, does 

 not, in my judgment, present any satisfactory distinctive features. 



The shell figured by Reeve under this name has the posterior ribs closer together 

 than in the types described by Sowerby. 



Cardita excavata, Deshayes. 



Cardita excavata, Desliayes, Proc. Zool. Soc. Lond., 1852, p. 100, pi. xvii. figs. 1-3. 

 Habitat. — Port Jackson, Sydney, in 2 to 10 fathoms. 



Three or four other forms of Cardita, viz., Cardita essingtonensis, Deshayes, Cardita 

 umbilicata, Deshayes, and Cardita pica. Reeve, are very closely allied to the present 

 species, and will probably eventually prove to be variations of the same shell. If the 

 spotting and fine reddish lines on the ribs of this species were not somewhat peculiar, I 

 should feel no hesitation in uniting it with Cardita essingtonensis or Cardita p)ica or 

 Cardita umbilicata, these so-called species evidently belonging to one and the same. 



