100 



DESCRIPTIONS OF NEW MOLLUSCA, 



Cruz and the Solomons. Mr. W. B. Hemsley has described a 

 remarkable Sapotaceous genus Chdonespermum, of which two of 

 the known species are from the Solomons and the third from 

 Fiji.* It is remarkable how strictly Nautilus observes as its 

 eastern limit the ancient coast line of the Melanesian plateau. 

 At a recent meeting of this Society! Mr. E. R. Waite exhibited 

 examples from Fiji of Typhlops aluensis, Blgr., a species previously 

 known only from the Solomon Islands. 



ISCHNOCHITON ARAUCAKIANUS, n.sp. 



(Figs. 3-6.) 



Shell oval, depressed, valves rounded posteriorly, but the 

 anterior ones more pointed. Colour greenish-grey, each valve 

 shading posteriorly into cream, with a median wedge of black, 

 which is sometimes split with a central white stripe. Interior 



dull purple, shading posteriorly into brown. Girdle (fig. 6) 

 chequered black and cream. Lateral areas elevated with about 

 three obscure, diverging lines of granules, more prominent on 

 the anterior valves. Central areas finely and evenly corded trans- 

 versely. Anterior valve radiately tuberculated. Posterior valve 

 (fig. 4) with subcentral mucro, anterior area concentrically striated, 

 posterior concentrically tuberculated, the mucro is eroded in 

 specimens studied. Anterior and posterior valves with eight slits, 

 median with one; teeth finely pectinated and roughened with 



* Joarn. Linn. Soc. Botany, xxx. 1894, p. 164. 

 f See Vol. xxii. p. 685. 



