67 



*** Scales o/the margin transversely c/rooved; valve rounded, not 

 keeled, thin. 



This section forms a very natūrai group. 

 Ch. textilis, Gray, Spic. Zool. = Ch. longicymba, Blainv., Qmy. 

 Ch. Indicus, Sow. C. III. f. 55. Ch. Solea, Sow. C. III. f. 61, Cape 

 of Good Hope. 



Ch. Magdaliensis, Hinds. 



**** Scales of the margin lanceolate, elongate, erect, closely pressed, 

 Ch. laevis, Mont. =Ch.. corallinus, Risso. 



2. ToNiciA, Gray, Syn. Chiton, Risso, E. M. 267. 



* Valves broad, transverse. 



T. atrata. Ch. atratus, Sow. C. IllusL i. 57, 58. Falkland Islands. 



T. elegans. Ch. elegans, Fremhly, Sow. C. Illust. f. 73, 74. Ch. 

 Chiloensis, Sow. Ch. lineolatus, Fremhly. Ch. graniferus. Sora. Ch. 

 Sparius, S>ow. Conception Bay. 



T. rubra. Ch. ruber, Linn. Ch. marmoreus, O. Fal. Ch. latus, 

 Lowe, Ch. fulminatus, Couih. 



T. fulva. Ch. fulvus, Wood, Sow. C. III. f. 53. Cadiz. 



T. lineata. Ch. lineatus, Wood, Sow. C. III. f. 77. 



T. Swainsonii, Sow. C. III. f. 5. Peru. 



T. cerasina. 



T. laevigata. Ch. laevigatus, Flem. 



T. lyrata. ^ 



T. Grayii. Ch. Grayii, Sow, C. Illust. f. 8—16. Peru. 



T. castanea. Ch. castaneus, IVood, Sow. C. Illust. f. 114, 115, 

 116. Cape of Good Hope. 



T. fastigiata. Ch. fastigiatus, Gray, Sow. C. Illust. f. 11. Cali- 

 fornia. 



** Valves moderate, subcordate, rounded, and f ar apart on the sides ; 

 lobes of insertion wide ; mantle broad. 

 T. disjuncta. Ch. disjunctus, Frembly, Zool. Journ. t. 77. f. 5, 

 forms the passage to the Chitons, which have only a small part of the 

 valves exposed. 



3. AcANTHOFLEUKA, Guild. Z. J. V. 27 ; Gray, Syn. 

 Canthapleura, Suiains. 



This genus gradually passes to Onithochiton. 



* The plate of insertion of the hinder valve mell-developed, regular ; 

 valves thin ; lateral area distinct ; margin bristly. 



A. Peruviana. Ch. Penivianus, Lam., Sow. C. III. i. 44. Peru. 

 A. bicolor. Ch. bicolor, Adams. West Indies. 

 A. Hennahi. Ch. Hennahi, Gray, Sow. C. III. f. 1 & 33. 

 A. Watsonii. Ch. Watsomi, Sow. C. III. i. 81, 82, 130 = Ch. cas- 

 taneus, Quoy. 



No. CLXXIV. — Proceedings of the Zoological Societt.. 



