166 



Measurement. — Dried, 8x4 mm. 



Hab. — Dredged by Dr. Verco from 130 fathoms off Cape 

 Jaffa. Several valves were dredged from 300 fathoms off the 

 south-east coast of South Australia. 



Remarks. — In detail this shell strongly resembles Lepi- 

 dopleurus inquinatus, but the whole shell is much more carin- 

 ated and the lateral areas differ in the massing of the 

 pustules. 



57. Ischnochiton bednalli, sp. nov. PI. v., figs. 3a-/. 



General Appearance. — Elliptical, valves wide, rounded, 

 slightly carinated, side slopes curved, cream colour uniform 

 in valves and girdle. The posterior margins of the valves pro- 

 ject considerably and give a verandah-like appearance. The 

 valves are exceedingly delicate. 



Anterior Valve. — Two or three ill-developed grooves or 

 growth-lines parallel to the girdle crossed by about twenty 

 microscopically pustulose lirae converging towards the apex. 

 About twenty slits with regularly scalloped pectination 

 between. 



Median Valve. — Dorsal area uniform in width composed 

 of five or six rows of pustules either worn or compressed. 

 Pleural areas divided into five irregular diagonal rows of 

 pustules by reticulated sulci, which gives the appearance of 

 open network. Lateral areas distinctly raised and crossed 

 transversely with four rows of pustulose lirae converging 

 towards the dorsal area. Four of these pustules project from 

 the posterior margin. Interior pearly-w r hite. Valves pro- 

 ject considerably. Sutural laminae small and delicate. Sinus 

 very wide. Diminutive slit rays under J-in. lens. 



Posterior Valve. — Mucro ante-median almost covered by 

 the seventh valve. Concave between the mucro and the 

 girdles. The mucro is covered with pustules, and the rest 

 of the valve has two or three concentric rings of pustulose 

 lirae parallel to the girdle. The pustules grow smaller towards 

 the mucro. About twenty-six slit rays. 



Girdle. — Covered with microscopically striated, scales. 



Hab. — Two specimens only from St. Francis Island, 

 Nuyt Archipelago, Australian Bight. 



Measurement. — Dried specimen, 6x3 mm. 



Remarks. — I have named this chiton after Mr. Bednall, 

 the doyen of Polyplacophora work in Australia. It is an 

 exquisite chiton, and somewhat resembles Ischnochiton 

 pilsbryi and Lepidopleurus inquinatus. 



