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



Kellia rotunda, (Deshayes), var. (PI. XI. figs. b-bh). 



Erycina rotunda, Desliayes, Proc. Zool. Soc. Lond., 1855, p. 18L 

 Kellia rotunda, Angas, Proc. Zool. Soc. Lond., 1867, p. 927. 



Habitat. — Station 162, off East Moncoeur Islaucl, Bass Strait, iu 38 fathoms 

 (Challenger) ; Port Jackson (Challenger and Angas) ; also Newcastle, New South Wales 

 (Angas) ; Moreton Bay (Deshayes). 



The single specimen obtained by the Challenger at Port Jackson is considerably 

 larger than any other that I have ever seen, and exceeds the dimensions of the types 

 described by Deshayes. It is 14 mm. in length, nearly 13 high, and 8 in diameter. 

 The form is hardly as rotund as that of the Moreton Bay specimens, for with age the 

 posterior side appears to enlarge more rapidly so that the large shell under examination 

 is rather more inequilateral. The specimens from Bass Strait exhibit a precisely similar 

 outline, and consequently approach very closely the Kellia cycladiformis of New Zealand, 

 and, indeed, I am rather inclined to believe that they will prove eventually variations 

 of one and the same species. The specimen in Mr. Cumings' collection from North 

 Australia (Jukes), assigned by Deshayes to his Erycina cycladiformis, is very different 

 in form from the shells from New Zealand. It is rounder, having the anterior end 

 narrower than the posterior, which is the reverse in the latter s^iecimens as a rule, and 

 not weU shown in Deshayes's figure. Among a series of Kellia cycladiformis from New 

 Zealand, presented to the British Museum by Colonel Bolton, there is a specimen of 

 unusually large size, whose dimensions are worth recording. It is 17g mm. long, 15 

 high, and 11 in diameter, an averaged sized specimen being about 12 in length, 10 iu 

 height, and 8 in diameter. The hinge-characters are precisely similar in l)oth forms. 



Kellia cardiformis, n. sp. (PI. XI. figs. 6-66). 



Testa globosa, fere sequilateralis, tenuis, subcircularis, alba, liris confertis radiantibus 

 tenuissimis ornata, incrementique lineis concentricis sculpta. Umbones leviter supra 

 marginem dorsalem producti, ad apices obtusi, politi. Latus anticum regulariter 

 arcuatum, posticum altius, minus curvatum, superue obtuse humerosum. Denies 

 cardiuales valvse sinistrse duo subvalidi, partem anticam versus inclinati, in dextra unicus 

 obliquus, subbipartitus ; dens lateralis posterior in utraque valva elongatus, gracilis, in 

 sinistra margine dorsali sulco angusto separatus. 



This little Cardium-like species is very thin, rather globose, somewhat circular and 

 nearly equilateral. It is whitish, slightly glossy, sculptured with very fine radiating 

 sulci with intervening rounded ridges which are crossed by fine concentric lines of 

 growth. The hinder dorsal margin is higher than the front and less oblique, and joins 



