BY C. HEDLEY. 



699 



Subemarginufa parmophoidea, now shown to be a different Aus- 

 tralian species. 



Hemitoma aspera Gould. 

 (Plate xlvi., fig.6.) 



In the last Part of these Studies {aiitea, xxxix, p.707), it was 

 stated that, though in ordinary use, Subemarg inula was unten- 

 able Relying on a defective entry in Scudder, Montfortia was 

 selected to replace it. Messrs. W. C. Clapp and T. Iredale have 

 kindly written to say that the name Rafinesque proposed was 

 not Hemitoma, as Scudder quotes, but Hemiloma. Therefore 

 the Hemitoma of Swainson, not Montfortia of Recluz, must take 

 the place of Suhemarginula. For the group of H. rvgosa, Mr. 

 Iredale has introduced Montfortula* 



H. aspera inhabits the crevices among the compacted tubes of 

 Galeolaria,-\ where it is common near Sydney. When warned, 

 it can clino^ tenaciously to its foothold. Its movements are de- 

 liberate; both head and tail can be protruded beyond the shell. 

 Such parts as are exposed, the back of the head, tentacles, 

 siphonal pipe, and upper surface of hind foot, are black; the rest 

 is buff, which, on the mouth and muzzle, brightens to lemon- 

 yellow. The muzzle is rather long, with broadly expanding lip, 

 notched beneath. The tentacles are long and tapering; they 

 search actively in various directions; at the outer base of each 

 is a short, digitate, ocular tentacle with a large, black eye. On 

 the right side of this, there is, in the male, a curved, cephalic 

 appendage. Along the epipodial line, but interrupted between 

 the tentacles, runs a series of small, short filaments. When the 

 animal leans forward, the ctenidia are exposed; these are worn 

 folded, the edges doubled together on the inside and the stem 

 outside. Beyond the gill-tips, the mantle is slit, its edges 

 coalescing in a short tube external to the shell. The thickened 

 fringe of the mantle-margin is -produced into an inner and an 

 outer series of tufts of compound papillae, the outer ones lying 

 in the crenulations of the shell-rim. 



» Iredale, Trans. N.Z, Inst., xlvii., 1915, p.433. 

 t Hedley, Journ. Roy. Soc. N. S. Wales, xlix., 1915, p.66, P1.5. 



