132 



Las.s:a ktjbra, (Montague). 



Whether the little shell called Poronia australis by Sowerby 

 is distinct from the typical European species above named must 

 be left for more critical comparisons than I have been able to 

 make. But now that the distribution of L. rubra has been 

 better ascertained, and its existence in the Southern Hemis- 

 phere thoroughly authenticated, there seems very great reason 

 to believe that several species have been founded on examples 

 from our Australasian waters of this ubiquitous species. Forbes, 

 P. Carpenter, and other distinguished conchologists were 

 agreed as to its occurrence on either side of the IN". Atlantic, in 

 the Mediterranean, and in the Indo-Pacific region. Jeffreys 

 has just announced its presence in Korea Strait, along with 

 some other species common to the N. Atlantic and N. Pacific 

 Oceans ; and has ventured to express the opinion that these 

 forms have originated in high northern latitudes, and have 

 found their way to Japan on the one side and Europe on the 

 other by means of a bifurcation of the great Arctic current. 

 Jeffreys, moreover, extends its range to the Straits of Magellan 

 and to the Islands of St. Paul and Amsterdam. 



According to Gray, Cyclas australis, Lamk., from the Isle of 

 Timor, with a variety from King George's Sound (Peron), is 

 identical with the Cardium rubrum of the earlier English author ; 

 but so far as one can gather from Lamarck's diagnosis it is not 

 certain that it is so, as Lamarck has not mentioned the station 

 of his species. Deshayes considers the shell to be a Pisidium. 



The Lascea austrcdis (Sowerby) inhabits New Caledonia 

 (Sowerby), New South Wales (Angas), Tasmania ("Woods) ; 

 and I have collected it from Cape Northumberland to Eucla, 

 nestling among mussels or under loose stones, and in the 

 crevices of rocks above high- water mark ; and have received 

 specimens from King George's Sound. 



The South Australian and King George's Sound examples are 

 smaller than those from Tasmania, but exhibit considerable 

 variation in sculpture ; in some it is reduced to microscopic 

 concentric striae, and in others it is in the form of thick ribs. The 

 colour is sometimes white, though the red stain along the hinge 

 line remains. Eor these reasons, I cannot select any valid 

 character by which to separate L. australis and L. scalaris 

 (Phil.) from one another, and these names must go to swell the 

 long list of synonyms of L. rubra. 



Ptthina gemmata, nov. spec. PL v., fig. 8. 



Shell minute, oblong, inequilateral, thick, pellucid. Posterior 

 side the shorter, roundedly truncated ; anterior side produced, 

 rounded. Umbo subinflated. Ventral margin nearly straight. 

 Sciclpture, as viewed under an inch objective ; anterior and 



