27S i>nLVPi,vropHni;A of torp howe an'p Norfolk islands, 



iiig. At the Cascade landing place and in other positions more 

 exposed to the full force of the surf, mature examples are found 

 wedged in between the basalt boulders. These are mostly verj' 

 dark in coloiu-. and frequently eroded oi- covered with marine 

 growths. 



This shell appears to approach C. discolor Souverbie, of New 

 Caledonia, but differs from that species in the fewer radial ribs 

 on the end valves, and the fewer and less anteriorly prolonged 

 sulci in the central areas. Chiton canaliculatus Quoy and 

 Gaimard, from New Zealand, is also related, but is more elevated 

 and shai'per-keeled, and has a harsher sculpture. A similar, if 

 not identical, species was found by Mr. T. Iredale on Raoul or 

 Sunday Island, Kermadec Group.* 



7. Chiton howensis, n.sp. 



(Plate xiii., figs. 7, 7rt, 71), 7c, 7d, 7e, 7/j 7g.) 



Shell strongly elevated, carinated, side slopes curved and steep. 

 Colour very variable, creamy white, maculated with pink, purple, 

 or brown, chietiy on the end valves and lateral areas; central 

 areas green, jugal tract paler, tlie whole shell finely mottled in 

 colour. 



Anterior valve with 8-10 somewhat irregular wavv concentric 

 riblets. 



Posterior valve : mucro prominent, in front of the centre ; 

 posterior slope convex, concentrically ribbed similarly to the 

 anterior valve, but with slight radial depressions. 



Median valves strongly i-aised, deeply transversely ribbed with 

 irregular wavy riblets which are traversed by a shallow depres- 

 sion. Central areas smooth; jugal tract finely transversely striate. 



Girdle irregularly tesselated with broad bands of purple-brown, 

 with scattered deep green scales. Scales small, densely imbricat- 

 ing, striate, polished on the margins. 



Interior bluish-white; sinus broad, denticulate. Anterior valve 

 having 10, median valves 1-1, and posterior valve 12 slits. Teeth 

 very finely pectinate on the edge. 



* Iredale, Proc. Malac. Soc. ix, 1910, p.l61. 



