136 DR JAMES COSMO MELVILL AND MR ROBERT STANDEN ON THE 



In all the specimens examined of our proposed variety, the ribs are but twelve in 

 number ; in typical C. pallida, Sm., they number fourteen to fifteen. The straight 

 angular declivity on either side of the dorsal margin seems likewise more pronounced, 

 the variety thereby assuming a more flabellate or quasi-triangular appearance. The 

 general characters of the shells are identical. As Mr SMITH aptly remarks, the 

 superficial aspect of Cardita flabellum, Reeve,* proves it to be nearly allied. This is 

 a native of Valparaiso, Chili. 



Cardita congelascens, sp. n. (Plate, fig. 23). 



C. testa parva, trapezoide, solidula, umbonibus prominulis, inequilateral!, sequivalvi, postice dorsaliter 

 recta, antice breviter arcaata, deinde ventralem usque ad marginem, leniter subrotundata, superficie 

 radiatim costulata, costulis inorassatis, numero ad 21, pulchre et regulariter nodulosis, nodulis imbricatulis, 

 albis, nitidis pagina intus alba, valva dextra, cardinalibus dentibus duobus crassis, sinistra dente crasso, 

 elongate, prseditis 



Alt. 3, diam. 4 mtn. (sp. maj.). 



Hab. Burdwood Bank, south of the Falkland Islands, at 56 fathoms. Station 346. 



Only disassociated valves occurred of a species of Cardita which seems distinct. 

 We have compared it with C. modesta, nelutina, antarctica, astartoides, and other 

 species of the genus inhabiting these same southern waters, and find it fails exactly to 

 correspond with any of them. At the same time, we doubt if any of our examples are 

 adult. Still, the character of the ribs, and the ornamentation and the general contour 

 of the shell, give us hope that it may be proved eventually to have been established 

 on a sound basis. The specific name alludes to the icy clime where it is endemic. 



Family Astartidas. 

 Astarte magellanica, Sm. 



s 



Astarte magellanica, E. A. Smith, Proc. Zool. Soc. Land., p. 41, pi. v. fig. 7 (1881). 

 ,, ,, ,, Journ. of Conch., iii. p. 227. 



Hob. Burdwood Bank, south of the Falkland Islands, at 56 fathoms. Station 346. 



All disassociated valves, but some in good condition, and showing the olivaceous 

 epidermis. The majority possess fewer concentric ribs than the type, but we consider 

 them all referable to magellanica. The allied A. longirostra, Orb., also found in this 

 region, is more pronouncedly beaked, and the ribbing is far finer. The crenulation of 

 the inner margin of the valves is, as pointed out by the author of the species, another 

 distinctive factor in A. magellanica. 



* Reeve, Conch. Icon., i., Cardita, pi. ix. fig. 47 (1843). 



(ROY. 8OC. EDIN. TKAN8., VOL. XLVIII., 362.) 



