132 Zoological Society. 



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



* Valves broad, transverse. 



T. atrata. Ch. atratus, Sow. C. Illust. f. 57, 58. Falkland Islands. 



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

 Chiloensis, Sow. Ch. lineolatus, Frembly. Ch. graniferus, Sow. Ch. 

 Sparius, Sow. Conception Bay. 



T. rubra. Ch. ruber, Linn. Ch. marmoreus, 0. Fab. Ch. latus, 

 Lowe. Ch. fulrainatus, Couth. 



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. laevigatas, Flem. 



T. lyrata. 



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



T. castanea. Ch. castaneus, Wood, 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 far 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. AcANTHor-LEURA, Guild. Z. J. v. 27 ; Gray, Syn. 

 Canthapleura, Swains. 



This genus gradually passes to Onithochiton. 



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

 valves thin ; lateral area distinct ; margin bristly. 



A. Peruviana. Ch. Peruvianus, Lam., Sow. C. III. f. 44. Peru. 

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

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

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

 taneus, Quoy. 



** The plate of insertion of the hinder valve narrow, rather irregular. 



f Margin bristly ; lateral area distinct. 



A. nobilis, Gray. New Zealand. 



ft Margin spinose or spinulose ; lateral area indistinct. 



A. picea. Ch. piceus, Sow. C. III. f. 147. West Indies. 

 A. spinigera. Ch. spinigerus, Sow. Conch. III. f. 68. Peru. 

 A. Owenii, Gray. West coast of Africa. 



A. spinosa. Ch. spinosus, Brug., Sow. C. Illust. f. 151. Australia. 

 A. brevispinosa. Ch. brevispinosus, Sow. C. Illust. f. 136. Island 

 of Johanna. 



A. magnifica. Ch. magnificus, Gray, Sow. C. Illust. f. 52. 



