21-2 THE VOYAGE OF H.M.S. CHALLENGER. 



epidermide olivacea induta, costis radiantibus tuberculatis circiter undeviginti instructn, 

 incrementi lineis in interstitiis sculpta. Luuula parva, fuscescens, elongato-cordata, 

 impressa. Margo dorsi posticus rectiusculus parum obliquus, anticus leviter concavus, 

 valde declivis, brevior. Latus posticum latum, rotunde subtruncatum, anticum angustius 

 rotundatum. Margo ventris late curvatus. Umbones in. circa ^ longitudinis collocati. 



This species is considerably longer than high, somewhat square, broader behind 

 tiaan in front, very inequilateral, and moderately convex. It is white, sjjotted upon the 

 ribs with pale red, and more or less covered with an olive epidermis. The sculpture 

 consists of about nineteen radiating costas, which are rather slender, about as broad as 

 the intervening sulci, and covered with small compressed nodules. In addition the 

 grooves are crossed with rather strongly marked lines of growth. The kxnule is generally 

 tinged with brown, somewhat impressed, and elongate cordiform. The beaks are placed 

 well towards the front, being about one-fourth of the length from that extremity. 

 The central tooth of the right valve is large, white, acute above, and triangular, the two 

 of the left valve diverging, and much smaller. The muscular scars are orange or bi-owu, 

 and the inner margin of the valves is strongly dentate. 



Length 13 mm., height 11^, diameter 9. 



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



This species was originally described by Deshayes from specimens said to have been 

 collected in New Zealand, a locality not since confirmed, for Captain Hutton, in his 

 Manual of New Zealand MoUusca, includes this species in the fauna of that country 

 merely on the authority of the type-shells. 



Cardita astartoides, Martens (PI. XV. figs. 2-2c). 



Cardita astartoides, Martens, Sitzungsberichte Gesellscli. Nat. Freunde, Berlin, 1878, p. 25. 



Testa suborbiculata, crassa, antice et postice subsequaliter rotundata, margine dorsali 

 antico concavo, postico convexo, gibbo, margine ventrali sequaliter arcuato ; costis radianti- 

 bus latiusculis circa 18, parum elevatis, interstitia subsequantibus et lineis concentricis 

 undulatis costas seque ac interstitia percurrentibus sculpta, periostraco crasso, uigrofusco 

 costas suboccultante vestita. Dens cardinalis medius valvse dextrte interdum distincte 

 bifidus, anticus valvse sinistrae subvalidus, trigonus, lateribus perpendiculariter decisus ; 

 impressio muscularis antica elongata, postica brevior. 



Length 31 mm., height 27, diameter 15. 



Habitat. — Station 149, Eoyal Sound, at Balfour Bay, Kerguelen Island, in 20 to 60 

 fathoms ; and Station 150, between Kerguelen and Heard Islands, in 150 fathoms. 



This species, as pointed out by Martens, bears a great resemblance to the Nortli 

 American Cardita borealis of Conrad, and may be regarded as the southern representa- 



