G9 



8. Enoplochiton. 

 E. niger. Ch. niger, Bames. Ch. Coąuimbensis, Frembly. Co- 

 quimbo. 



The valves become very much eroded. 



9. MOPALIA. 



Valves broad, transverse, depressed ; margin of insertion moderate ; 

 the hinder valve •vvith a rounded lobe on the hinder edge ; mantle 

 moderately broad, bristly above, Earrow behind. 



* Margin moderately loide infront. 

 M. Hindsii. Ch. Hindsii. West coast of America. 

 M, Simpsonii. Ch. Simpsonii, Gray. Brit. Mus. 



** Margin very tvide infront. 



M. Blainvillii. Ch. Blainvillii, Sow. C. III. f. 6. Inner Lobos 

 Island. 



10. Katharina. 



K. tunicata. Chiton tunicatus, TFood, Conch. ii. t. 2. f. 1 ; Cat. 

 t. 1. f. 10. "VVood's specimen is now in the British Museum. 



K. Douglasiae. Ch. tunicatus, Sow. C. Illust. f. 152. Califomia. 



11. Cryptochiton. 



The gili only occupies the hinder part of the sides. 



C. amiculatus. Ch. amiculatus. Palias, Nov. Comm. Petrop. ii. 241 . 

 t. 7. f. 26, 30; Sow. Tank. Cat. (spec. Brit. Mus.) ; Wood, Cat. t. 1. 

 f. 12, inner side of shell; Sow. Conch. Illust. i. 80, half-grown. Chi- 

 ton Sitkensis, Reeve's Conch. Icon. f. 55, adult. Kurile Islands. 



12. Cbyptoconchūs, " Blainv.," Stoainson; Gray, Syn. 



Body oblong, rather convex ; back flattish or concave in the centre, 

 with the tuft of spines on the upper part of the sides of the back. 

 The gills extend about half the length of the sides. 



Cryptoconchus porosus, "Blainv.," Burroivs, Elem. Conch. 190 

 (1815), spec. Brit. Mus. Chiton porosus, Burroivs, E. C. t. 28; 

 Wood, Cat. t. 1. f. 39. Ch. Leachii, Blainv. D. S. N. 554, spec. Brit. 

 Mus. Ch, monticularis, Quoy, Voy. Astrol. t. 73. f. 30, 34, 36, and 

 lower fig. 7; Sow. Conch. Illust. f. 129, valves. New Zealand. 



13. Amicula, Gray, Syn. 1840. 



Body ovate, convex ; back convex ; mantle bristly. 



Amicula vestita. Chiton vestitus, Soįv. Zool. Journ. iv. 368 ; Sow. 

 Conch. Illust. f. 128. Ch. Emersonii, Couthoy. Atlantic Ocean. 



14. AcANTHOCHiTES, Leach, B.M. ; Gray, Syn. 



Acanthochites, " jLeacA." Acanthochitus, /žjsso. Phakellopleura, 

 Guild.,Swainson. Chitonellus (part.), Guild. Acanthochiton, /fernn. 



Body oblong, elongate, rather depressed ; mantle spinulose ; tuft 



