152 



PEOCEEDIXGS OF THE MALACOLOGICAL SOCIETY. 



Reeve, and on this authority I believe that species is included in 

 Mr. Adcock's list. A closer examination of specimens recently secured 

 at Sultana Bay proves that they are conspecific with C. Coxi, from 

 Port Jackson. 



Ilah. — Kangaroo Island and Southern Yorke Peninsula (South 

 (Australia) ; Port Jackson (New South Wales). 



It is a prettily-marked species, of a bronze-green colour throughout, 

 and is allied to the preceding. 



24. Chiton exoptandus, n.sp. PI. XII, Pig. 7. 



Oblong, strongly elevated with acute dorsal keel and straight side 

 slopes. Cream or brownish-white, heavily blotched on some valves with 

 reddish-brown, sparsely maculated with dots along the ridge, and more 

 or less mottled with the same colour or with j)inkish-brown on the other 

 valves, the markings tending to fonn arcuate 

 longitudinal streaks on the lateral areas and 

 end valves. Girdle rose - pui^ple or reddish- 

 brown, with whitish naiTower bars opposite 

 the sutures. A whitish wedge or triangle 

 spreads backward from the mucro on the tail 

 valve. Median valves acutely beaked (when 

 not eroded), the beaks but slightly projecting 

 on the straight or concave posterior margins 

 of valves, which at the sides are regularly 

 and closely serrate. Central areas with a smooth 

 wedge-shaped band along the narrowly rounded 

 ridge (wider and triangular in valve ii) ; the 

 pleura with about fourteen to eighteen strong, 

 narrow, rounded, longitudinal ribs, about as 

 wide as their intervals ; six or eight inner 

 grooves on each side, shorter, not extending 

 to the anterior edge of valves (short grooves on 

 valve ii more numerous) ; the grooves becoming 

 smaller towards umbones. Lateral areas well 

 raised, with some arcuate, coarse, irregular wrinkles in the direction 

 of growth-lines, bipartite by a median radial sulcus, more or less 

 interrupted into a series of triangular or long pits, whilst in some 

 specimens the areas are trisulcate on some or all valves. Yalve i, 

 short, erect, the anterior slope straight and shorter than the sutural 

 margins ; apex free and erect ; sutural margin emargiiiate ; sculptured 

 with eighteen to twenty radial, pitted grooves, the riblets more 

 or less crenulated. Valve viii, small, with post-central decurved 

 mucro, the posterior slope concave, sculptured with radial grooves and 

 riblets. Interior pink, or purplish where marked outside with brown ; 

 sinus extremely narrow (1mm. wide). Valve i with eight slits; 

 ii to vii, 1-1 ; \'iii, ten slits. Girdle clothed with very convex, smooth, 

 and polished scales, measuring slightly over -5 mm. in width. Length 

 27-28, breadth 14-15 mm.; divergence 97 degrees. 



Chiton exoptandus, 

 n.sp. 



