OP SOUTHERN INDIA. 273 



"Genera" do not say anything on this point, but simply take the figure of 

 A. sulcata from the Hist, of British MoUusca. Jeffreys in his British Con- 

 chology also follows in his account the same authors. I am not in a position to 

 doubt this record of the anatomy of A, sulcata, but I have lately receiyed from 

 my friend G. Nevill two species, one apparently A, semisulcata, Leach, and the 

 other most likely a variety of A. sulcata, Mont., from Greenland, both with 

 the animals beautifully preserved. In both these species the animals have a 

 strongly compressed, anteriorly pointed foot, a pair of narrow triangularly 

 elongated palpi on each side of the mouth the edge of which is finely cirrated ; 

 it is situated just behind the anterior adductor muscle; the gills are unequal 

 on either side, the outer leaflet being smaller, and both are pointed behind, reach- 

 ing almost below the posterior adductor muscle with their terminations. The man- 

 tle is open below in its entire extent, and has behind a small opening in which 

 terminates the anus, the rectum curving from above and being partially attached 

 to the hinder side of the posterior adductor. Thus these two species decidedly have 

 no siphons at all. The access of the water to the branchia is quite free below, and 

 the single opening must be considered as the anal one. This corresponds with the 

 account which Philippi gives in his '' Handbuch der Gonchiliologie," stating that 

 the AsTAETiB^ have no siphons. The next genus Gouldia, represented by the type 

 species Gouldia minima, Mont., sp., is, however, perfectly well known to possess 

 two very short or sessile fringed siphonal openings, very like those of Qyprina or 

 Corhicula, The species is, therefore, generally referred to the genus Circe, Schum., 

 and though in form it certainly appears much better to agree with Astarte, it shows 

 also great similarity to some species of that sub-genus, such as Circe divaricata and 

 others. Very probably this change in the classification has to be effected, and there 

 would be no particular objection to having it carried out in my present account, 

 if there was not another difficulty in the way which indeed it seems very difficult 

 to understand. 



Looking at the animals of Venericardia and that of Cardita, we find, so to 

 say, a similar contradiction as the one noted between Gouldia and Astarte. Becluz 

 (Journ. de Conch., 1862, x, p. 116,) says that Venericardia has only a simple 

 mantle-fold or single opening, while Cardita, fC antiquataj, as well as Mytili-^ 

 cardia, are said to possess two distinct siphons. 



I cannot say how far the accounts published regarding the anatomy of 

 CarditcB and similar forms are correct, but I will note the result of my observ- 

 ation. I have recently examined well preserved specimens of Cardita antiquata 

 (hicolor) sent to me by the Eev. Mr. Eairbank from Bombay. The animal has 

 the whole mantle open below and in front, posteriorly there is only one spacious 

 slit, in which the rectum terminates exactly as in Astarte ; the gills are elono-ated, 

 one pair on each side, the leaflets being rather unequal, pointed at the end, and 

 extend to below the commissure, where the edge of the mantle is finely ciliated ; 

 the palpi are small, high, and regularly triangular; the foot large, compressed, 

 pointed at the end, posteriorly with a byssal groove, and was folded over laterally 



