67 



from the late Mr. Bednall's collection, the material now being 

 in the hands of Mr. Iredale, and reported upon by him as 

 above. 



When in Philadelphia last year Dr. Henry A. Pilsbry 

 showed me some of the material that Mr. Bednall had sent 

 him (at the time the description of S. pilsbryanus was written) 

 as being the new shell. I easily identified in the material 

 shown to me the three species S. juloides, Ad. and Ang. ; 

 S. cymodocealis, Ashby; and S. posidonialis, Ashby; all very 

 small and juvenile. 



It is therefore fairly evident that Mr. Bednall's drawings 

 and descriptions were made from more than one specimen 

 covering more than one species. I think it not unlikely fahati 

 there was even a fourth species represented, as I did not see 

 all the material. I therefore propose to refer the species I 

 am describing hereunder to Mr. Bednall's species for the 

 following reasons : — 



(1) I am anxious to retain the names of my friend 



Dr. Pilsbry and my late friend Mr. Bednall as 

 associated with the interesting genus of Stenochiton. 



(2) It is desirable to keep our list of species free from 

 those that are impossible of identification. 



(3) The form I am describing corresponds most closely 

 with the figure of the shell in Mr. Bednall's paper. 



(4) Mr. Bednall's shell was practically from the same 



locality, 'Troubridge Shoal, St. Vincent Gulf, on 

 Zostera." Tapley Shoal is about 6 miles from 

 Troubridge. 



General appearance. — Broad and short, glossy, rounded, 

 without sculpture; the anterior valve unusually broad, the 

 last five valves tapering very slightly towards the posterior. 

 The general contour of the shell closely resembles that of 

 Terenochiton mattheivsianus, Bednall; at a distance of a couple 

 of feet it might easily be mistaken for that species. 



Colour and markings. — In the dried specimen with the 

 animal inside the anterior and posterior valves are antique 

 brown (Ridgway's colour standard), shading in the centre 

 valves to semi-transparent creamy-white, sparsely mottled 

 with pale olive-green. A number of reticulate whitish mark- 

 ings commence at the posterior margin of the dorsal area, and 

 spread fan-like anteriorwise. When disarticulated, and the 

 animal cleaned away, the shell is very transparent. The brown 

 anterior and posterior portions become pale-creamy and 

 olivaceous, and the central valves transparent white and' pale 

 olive. Two wavy (broadly V-shaped) bands traverse both 

 d2 



