262 



RECORDS OF THE AUSTHALIAN MUSEUM. 



Chiton torri, sp. nov. 

 (Plate lxxiii., figs. 6-11.) 



The individual figured is 15mm. long and 9 mm. broad. It 

 was taken at Hog Bay, Kangaroo Island, S. Australia, by Dr. W. 

 G. Torr and one of us during the Australian Association excur- 

 sion of the " Governor Musgrave " in January, 1907. Hitherto 

 it has been confused by local collectors with C. coxi, :i but we 

 regard it as a distinct species which replaces and represents G. 

 coxi in western waters. Instead of the usual diagnosis, it may 

 be better defined by the following comparison with related forms. 



Differential character's of Chiton jugosus, Gould, C. coxi, 

 Pilsbrv, and C. torri, H. & H. : — 



C. torri. 



C. jugosus. 

 Central area — 



Ribs high, rounded, 

 prominent, of the same 

 width the whole length. 

 Colour bright orange- 

 brown. Lines 10-14 on 

 large, 5-7 on small speci- 

 mens. 5-9 on posterior 

 valve. 



Sulci deep, wide, 

 colour blue. 



Anterior valve — 



Concentrically lined, 

 12-14 lines. 



Posterior valve — 



Mucro blunt, in front 

 of middle, posterior 

 slope slightly concave. 



Girdle scales — 



Large, convex, obso 

 letely striated, not 

 smaller towards the 

 outer edge. 



Small light coloured 

 triangle on tail valve, 

 extending broadly 



across girdle. 



Tegmentum — 



Minutely punctulate. 

 Interior — 



8-1-12. 



Ribs low, sloping 

 downwards, not promi- 

 nent. Colour: tine line 

 of dark olive green. 4-6 

 on median valves, 3-4 

 on posterior. 



Sulci shallow, narrow, 

 colour similar to main 

 body of shell. 



Concentrically lined, 

 6-S lines. 



Similar to C. jugosus, 

 but posterior slope even 

 less concave. 



Similar to C. jugosus. 



Wry faint small tri- 

 angle on tail valve, does 

 not extend over girdle. 



Minutely punctulate. 

 8-1-12. 



G. coxi. 



Ribs low, sloping 

 downwards, not promi- 

 nent. Colour: tine line 

 of dark olive-brown. 

 6-11 on median valves, 

 6 on posterior. 



Sulci very shallow 

 and broad. Colour 

 similar to main body of 

 shell. 



Smooth, finely reti- 

 culated. Colour of 

 body of shell. 



Mucro acute, central, 

 projecting, posterior 

 slope deeply concave. 



Dense, small, stri- 

 ated, slightly convex. 

 Smaller towards edge 

 of girdle. 



Light coloured tri- 

 angle on tail valve not 

 constant, and where 

 present a light l>ar of 

 even width crosses the 

 girdle. 



Minutely reticulate. 



8-l-(10-12). 



a Bednall— Proc. Malacol. Soc, ii., 1897, p. 151. 



