BY C. HEDLEY. 697 



rowly elongate, with the rostrum much less acute." By the study 

 of an authentic example of L. ensicula with which Mr. Fulton 

 favoured me, T am led to the conclusion that the genuine L. 

 ensicula is an absolute synonym of L. lefroyi Beddome, as Tate 

 and May had already declared it to be. Beddome's name is, con- 

 sequently, obliterated by priority. For contrast, the authentic 

 specimen of L. ensicula referred to is here illustrated (PI. Ixxviii., 

 figs. 15, 16); it is 11 mm. long, and 4*5 mm. high, and is labelled 

 as from J'ort Jackson. I have also seen the species from 63-75 

 fathoms, off Port Kembla, N. S. Wales, and from the Derwent 

 Estuary, Tasmania. 



The species left unnamed is here introduced as Poroleda 

 spathula; the type figured is 14 mm. long, and 4*5 high. 



I have also taken it outside Sydney Heads, in 80, and in 300 

 fathoms; and in 40 and 100 fathoms, off Cape Borda, South 

 Australia. 



Arca strabo, sp.nov. 

 (Plate Ixxviii., figs.l9, 20.) 



Shell small, solid, obliquely produced posteriorly, very inequi- 

 lateral, inflated, hinge-line straight, anterior end narrow, rounded, 

 posterior broad and obliquely truncated Epidermis dense, split 

 into long imbricating strips, which conceal the margin Sculp- 

 ture : low, broad, concentric ridges parting narrow furrows, and 

 traversed by radiate plications. Umbos approximating, pro- 

 minent, inflated, situated at about one-quarter of the length 

 from the anterior end. Ligamental area very narrow. Hinge 

 with a median toothless space, anteriorly four short irregular 

 teeth, posteriorly about eight narrow, much inclined, elongate 

 teeth. Inner margin of valve smooth, within the pallial line 

 radially scored. Length, 11; height, 6; depth of single valve, 

 3 mm. 



ifa6.— Several specimens dredged by self, 1913, from 100 

 fathoms, north-east of Port Macquarie, N.S.W.(type); and again 

 111 fathoms, east of Cape Byron, by Mr. G. H, Halligan. 



This species belongs to the section Cucullaria Conrad, the 

 other recent members of which are A. sagrinata Dall, from the 

 West Indies, and the Japanese A . dalli Smith. 

 5 



J 



