212 Southern Cross. 



LISSARCA AUCKLANDICA. 



(PI. XXIV., figs. 14, 15.) 



Testa minima, aequivalvis, valde inaequilateralis, convexa, purpureo-rufa, lineis 

 incrementi tenuibus, postice sublamellatis, sculpta, striis tenuissimis paucis 

 postmedianis radiantibus oniata ; imibones Icviter iM'omincntes, approximati 

 sed baud contigui ; denies utrinque circitcr quinque ; valvamim mavgines 

 (]irac:t,er jirojie ])artem anteriorem marginis ventralis et ad medium lateris 

 postici) intus fortiter denticulati. 



Longit. ^\ mm., diam. 2^ mm., alt. .3^ mm. 



Habitat. — Auckland Islands, 10 fathoms. 



Closely allied to L. rubro-ftisca (Smith),^ from Kerguelen Island, 

 but of a different form, being less oblong, having the umbones less 

 terminal and the hinge-teeth somewhat different. A faint depression 

 is observable extending from the umbo down the posterior end. 



PECTEN COLBECKI. 



(ri. XXV., fig. 11.) 



Testa tenuis, magna, compressa, rotundata, purpureo-rufa, costis radiantibus circitcr 

 18 subobsoletis, vel minime prominentibus instructa, concentrice C(mrertini 

 striata; margines dorsales nequales, late concavi ; linea cardinis aeque levicer 

 concava; auriculae subaequales, antica valva3 dextrae iufcrne baud profunde 

 sinuata ; pagina interna rufescens. 



Longit. 70 mm., alt. 70, diam. 1(3. 



Habitat. — Franklin Island, 10 fathoms. 



A large very thin species of which only a single right valve 

 was obtained. It is remarkable for its rich purplish red or 

 plum colour and the feebleness of tlie radiating costation. The 

 costae are somewhat more pronounced towards the umbo than upon 

 the rest of the surface, and are about twelve in number. Other 

 intervening and more feeble ribs are developed at a later period of 

 growth. The concentric sculpture consists of very fine thread-like 

 lamellae which are more remote in the early stages of growth than at 

 a later period. The auricles are striated with fine lines of growtli, 

 and anterior, in the vah;e described, exhibits a faint raised ray down 

 the middle. 



There does not seem to be any species bearing sufficient 

 resemblance as to suggest a comparison with the present form. The 

 Arctic P. grecnlandicus of Sowerby has even a tliinner shell, but in 

 size, colour, and sculpture is quite distinct. 



1 Pliil. Trans. Roy. Soc, 1879, Vol. CLXVIIL, p. 185, PL IX., fig. 17. 



