90 THE NAUTILUS. 



38. Carychium exile H. C. Lea. D, C. 



The aquatic species will be enumerated in a second paper. 



DESCRIPTION OF A NEW AUSTRiLIAN CHITON. 



BY H. A. PILSBRY. 



Chiton Bednalli n. sp. 



Oblong, strongly elevated, with acute dorsal keel and straight side- 

 slopes. Cream-white, with a small flesh-pink spot at each beak, and 

 a sparce mottling of same on lateral areas, the central areas clouded 

 with green. Girdle flesh-tinted with green bars. 



Median valves acutely beaked, the beaks hardly projecting on 

 the straight or concave posterior margins of valves, which, at the 

 sides, are regularly serrated. Central areas with a narrow, smooth 

 band along the ridge (wider and triangular in valve ii), the pleura 

 with 12 narrow, strong, rounded, longitudinal ribs on each side, 

 separated by flat grooves wider than the ribs ; inner one or two ribs 

 not reaching to anterior margin of valve. Lateral areas well raised, 

 divided by a median groove (doubled on some valves), which .u'i<les 

 at intervals, forming a series of triangular pits ; traces of somewhat 

 similar pits appear along the diagonal slope, and the posterior border 

 has a series of transverse undulations corresponding to the denticles 

 of the sutural margin. Valve i with about 20 radial narrow grooveSj 

 also pitted ; and, like the grooves of lateral areas, these do not extend 

 to the beak, which is surrounded by a smooth area. Valve viii with 

 central projecting mucro, the slope behind it very concave ; anterior 

 area ribbed, posterior area with pitted radial grooves. 



Interior white, blue on the valve callus. Girdle clothed with 

 convex imbricating scales, rounded in contour, and measuring about 

 two-fifths of a millimeter in width, faintly striated toward inner 

 edge of girdle, blunter and smoother toward outer edge. 



Length 25, breadth 11 mm. ; angle of divergence 98. 



Yorke's Peninsula (W. T. Bednall). 



This species resembles C. Coxi somewhat, but differs in the pecu- 

 liar pit sculpture of the lateral areas. Its nearest ally is a still un- 

 described South Australian species collected by Mr. Bednall. The 

 coloration described will probably be found subject to variation, as 

 usual. 



