46 



RECORDS OF THE AUSTRALIAN MUSEUM. 



interlocking tubercles, which are probably the homologues of what 

 Bernard described as the dysodont teeth of Fhilohrya. Three or 

 four radial grooves and complementary ridges, directed to the 

 extreme ventral margin, which they undulate, traverse the interior, 



Fig. 9. 



Adacnarca sqiiamea. 



but are not visible externally. Perhaps the interlocking tubei'cles 

 aid the weak hinge by clasping the ventral margins. Pallial line 

 indistinct. Anterior and posterior adductor scars pi'esent, situated 

 high up. Height, 1'8; length, 1-81 ; depth, 0-5 mm. 



The genus Adacnarca was formed by Prof. P. Pelseneer for the 

 reception of a larger species taken by the Belgica Expedition.^ 

 It appears to me to belong to the sub-family Philobryinae, froni 

 the known members of which it chiefly differs by its greater 

 symmetry. Hochstetteria forms a link between it and the more 

 eccentric Philohrya. Some chai-acters of Adacnarca suggest a 

 more distant relation to the Limopsida?. I would prefer to range 

 the Philobrj'infe rather with the Taxodonts like Pelseneer than 

 with the Pearl shells like Bernard. Indeed an ideal sketch of 

 the primitive Taxodont stage by H. Fischer* would almost serve 

 as a picture of our shell. 



Prof. Paul Pelseneer has very kindly compared specimens of this 

 with his type. He remarks (5 April, 1905) that the hinge of the 

 Australian species is shorter, and that the two stiiated plateaux 

 on either side of the ligamentary fossette are higher than in the 

 type. These differences he regards as specific, and accepts the 

 species for inclusion in his genus. 



LiMEA ACCLINIS, sp. nov. 



(Fig. 10). 

 Shell small, thin, oblique, inequilateral, subangled anteriorly, 

 externally resembling L. linguatula, Lamk. Colour white. Sculp- 

 '" Adacnarca nitens, Pelseneer — Voy. " Belgica," Moll., 1903, p. 24, 



pi. vii., f. 83. 

 * Fischer — Journ. de Conch., xlv.. 1897, p. 211, f, 1. 



