98 ISCHNOCHITON. 



The granules of the surface have an irregular concentric disposi- 

 tion, following to some extent the lines of growth. (Smith.) 



Port Curtis. 



Chiton (Ischnochiton) curtisianus SMITH, Rep. on Zool. Coll. H. 

 M. S. 'Alert,' p. 78, t. 6, f. D. 1884. 



This is certainly not a typical Ischnochiton. It is difficult, with- 

 out an examination of a specimen, to refer it to its proper genus. 



I. EXIGUUS Sowerby. PL 23, figs. 85, 86. 



Shell oblong, small, rufescent, narrow. Intermediate valves hav- 

 ing a very wide trigonal dorsal carina,the margins grooved ; lateral 

 areas distinctly defined. Length 4'1, breadth 1-3 mill. (Sowb.) 



This is the smallest species Mr. Sowerby has seen ; the dorsal 

 keel of the intermediate valves is very broad, and distinguished by 

 a groove on each side. (Sowb.) 



Lord Hood's Island, Polynesia, on Pearl Oysters. 



Chiton exiguus SOWB., P. Z. S. 1832, p. 104; Conchol. Illustr. f. 

 36, REEVE, Conch. Icon. t. 28, f. 186. Ischnochiton exiguus CPR., 

 MS. 



Carpenter writes : Interior: end valves having 14-16 slits, cen- 

 tral valves 1 slit ; sinus wide, curved ; girdle irregularly clothed 

 with large, slightly striatulate scales. Habitat, Central Pacific 

 {Pease). Mr. Pease's solitary specimen seems conspecific with Mr. 

 Cuming's hitherto unique specimen from Lord Hood's Island. It 

 is in better condition than the type, but extremely minute and evi- 

 dently very young. 



2. Group of I. textilis. 



Central areas granulated, becoming striolate at the sides; lateral 

 areas radially wrinkled. South African species. 



I. TEXTILIS Gray. Unfigured. 



Shell oblong, elongate, white, pellucid when young, green with a 

 uhite central band ; convex above ; end valves and lateral areas of 

 the middle valves finely radiately striated and concentrically 

 wrinkled ; central area closely and minutely punctated, and behind, 

 finely longitudinally striated ; margin [girdle] white, minutely scaly. 

 Length one inch and a half. (Gray.)* 



Cape of Good Hope (Capt. Carmichael, Mus. Brit.). 



Chiton textilis GRAY, Spicilegia Zoologica, pt. 1, p. 5, pi. 6, f. 20 

 (July 1, 1828). KRAUSS, Die Su'dafric. Moll., p. 38. (?) Ch. solea 



