REPORT ON THE LAMELLIBRANCHIATA. 213 



tive of that form. It certainly is more like that species than Cardita velutina, Smith, 

 from South Patagonia, which we should not expect, considering how similar tlic fauna of 

 that region and of Kerguelen Island appear to be. 



Cardita astartoides is a much flatter and larger species than the Patagoniau shell, 

 and has much feebler radiating ribs. 



The young of this species is clothed with a straw-coloured epidermis, and appears to 

 be proportionally longer than the adult shell. 



Cardita sp. 



Habitat. — Port Jackson, iu 2 to 10 fathoms. 



Only a single right valve of this species, which I have not been able to identify, was 

 obtained. It is scjuarish behind, narrowed in front, and covered with about twenty 

 slender ribs, bearing numerous prickly hollow scales. The intervening sulci are deep, 

 and just a trifle broader than the costse. It is whitish and spotted with pale red upon 

 the ridges, and the minute sunken cordate lunule is also stained with the same colour. 

 The interior is faintly radiately grooved, the grooves corresponding to the external ribs. 

 Length 9 mm., height 7. 



Cardita dilecta, n. sp. (PI. XV. figs. 4 -4a). 



Testa mediocriter insequilateralis, subglobosa, parum crassa, antice rotundata, postice 

 latior, minus rotunda, costis circiter 28 confertis, minime elevatis, striis concentricis 

 numerosissimis sculptis instructa, albida rufofusco irregulariter notata et maculata. 

 Lunula subprofunda, elongato-cordata. Margo dorsi posticus obliquus, rectus, anticus 

 valde declivis, vix concavus. Pagina interna albida, plus minusve rufo tincta, margine 

 denticulato circumdata. 



This little Carc^m ni-shaped species is rather thin and inequilateral, whitish or whitish- 

 i)rown, variegated with short streaks of reddish-brown on the costse, and stained down 

 the posterior side with the same colour. It is sculptured with narrow radiating impressed 

 lines, which leave between them about twenty-eight very little elevated round-topped 

 ribs which are cut across by very numerous concentric striae, producing very narrow 

 transverse tubercles upon the costse. The tubercles are about equal iu width all over the 

 valves, but a few down the hinder side are separated by rather broader grooves than the 

 rest. The lunule is moderately deep and elongate heart-shaped. The hinge consists of a 

 single conical cardinal tooth in the right valve, which fits in between two teeth in the 

 left valve, whereof the posterior is very long and slender, forming the lower support of 

 the ligament. The interior appears to be whitish, and more or less tinged with red. 



Length 8 mm., height 6, diameter 5^. 



