o4 THE VOYAGE OF H.M.S. CHALLENGER 



increasing in number by the intercalation of shorter ribs. Apophysary system in dorsal 

 valve consisting of two short, central, diverging branches, forked at their extremities. 

 Interior surface tuberculated, a row of short, erect spine-like asperities rising perpendicu- 

 larly close to, and all round the inner margin of valves. Its brachial appendages are 

 small, the central spiral lobe especially so. Shell perforated by small canals. Length 7, 

 breadth 7, depth 4 mm. 



Habitat. — Five specimens of this small species were brought home by the Challenger 

 Expedition attached to specimens of Waldheimia Jlavescens. They were obtained on 

 June 3, 1874, at Port Jackson, near Sydney, South Australia. The specimens of Wald- 

 heimia being found close to the shore. The Eev. T. E. Tenison Woods, F.G.S., states 

 in his Census of the Marine Shells of Tasmania and Adjacent Islands (p. 34, 1877), 

 that Kraussina lamarckiana occurs in abundance under stones at low water at Tamar 

 Heads, also in South-East Australia and New Zealand, and occasionally at Long Bay. 



Observations. — Kraussina lamarchiana is distinguishable from Kraussina pisum, 

 Lam., by its much smaller dimensions and comparatively stronger ribs. A very closely 

 allied species, or variety of Kraussina lamarchiana, to which M. Vdlain has given the 

 name of davidsoni in his valuable Malacologie de I'lle de St Paul, occurs in vast 

 abundance on the shore in the interior crater of the Island of St Paul. M. Velain informs 

 me that after having examined many hundred specimens, and compared them with the 

 Australian Kraussina lamarckiana, he had determined to raise the St Paul shell to the 

 rank of a new species. That during the ordinary low tides they are scarcely covered by 

 water, and are alternately covered and left bare at the ebb and flow of the tide. They 

 occur in an area of a few yards' width, and, consequently, at very shallow depth, doubtless 

 because they find there those conditions to which they are accustomed in other localities. 

 M. Velain informs me that during his lengthened stay at the Island of St Paul, no other 

 species of Brachiopod was dredged, that the shell referred to by Mr Dall as Kraussina 

 picta, Val., Verh. Zool. Bot. Ges. Wien., p. 894, 1865, as from the Island of St Paul has 

 been nowhere described, and thus that name must be attributed to an incorrect citation. 



Kxmssina pisum, Val. apud Lam., sp. (PI. IV. figs. 7, 8). 



Terebraiula pisvm, Val. apud Lam., Anim. sans Vert., vol. vi. p. 330, 1819. 



Terebratula natalensis, Kiister, 1843, and Krauss, Die sudafricanschen MoUuskeu, pi. ii. fig. 11, 1848. 



Krmissla pisum, Dav., Ann. and Mag. Nat. Hist., vol. ix. p. 370, 1852, and Eeeve, Mou. of Tere- 



bratula. Conch. Icon., pL ix. fig. 26. 

 Kraussina pis^im, Dall, Am. Journ. of Conch., vol vi., part 2, p. 140, 1870. 



Shell suborbicular, or oval, often rather wider than long, yellowish-white ; dorsal 

 valve very slightly convex with a groove-like central, longitudinal depression extending 

 from the umbo to the fi-ont. Hinge-line nearly straight, and rather more than half as 

 long as the breadth of the shell. Ventral valve deeper than the dorsal one, longitudinally 



