CH^TOPLEURA. 39 



valves and teeth are broken. The figures here given are from 



Reeve. 



C. SOWERBIANA Reeve. PL 13, figs. 67, 68. 



Shell oblong-ovate, valves having the lateral areas conspicuously 

 elevated, granosely ridged throughout, ridges of the central areas 

 much finer. Dull yellowish-brown, with a triangular whitish spot 

 along the umbonial summit of each valve. Ligament horny. 

 (Eve.} 



Rio Janeiro. 



Chiton janeir ens is Gray, REEVE, Conch. Icon. t. 15, f. 80. C. 

 sowerbianus REEVE, L c., in note under species No. 116, May, 1847. 

 Sowerbyi REEVE, 1. c., expl. of pi., detail of sculpture, sp. 80. 

 Sowerbyanus REEVE, /. c., index to Chiton. 



Carpenter says : Seems to me a coarse var. of spinulosa Gray. 

 Rio Janeiro. Very like apiculata, but with more swelling side areas. 

 The sinus represented in the sculptured figure of Reeve is only the 

 part left after the swelling of the sides. With this impression, I 

 did not think it necessary to examine the single specimen in Cum- 

 ing's collection ; but on further examination I thought it might be a 

 distinct species and described it thus : Valves arched ; jugum rather 

 rounded ; jugular area finely striate. Central areas having about 

 18 nearly parallel ribs on each side, the interstices decussated 

 between the ribs, which are sharp (not in necklaces). Lateral 

 areas swelling, with 6 to 8 very close rows of coarse granules, inter- 

 calating, and no spaces between. In the end valves they go into 

 close radiating rows. Mucro in front of the middle, depressed, the 

 slope behind it very concave. Girdle with very few scattered hairs. 

 Interior: Anterior valve with 9, central 1, posterior 8 slits; teeth 

 sharp, normal ; eaves conspicuous, rugulose, but not spongy. Sinus 

 moderate, sharp, deep, channelled. 



Length 26J, breadth 13 mill. 



C. ARMILLATA Carpenter, n. sp. Unfigured. 



Shell subelongate, elevated, the jugum acute; mucro a little in 

 front of the middle; reddish-brown, maculated with darker. 

 Valves quadrate, scarcely apicate ; jugal area scarcely defined; 

 central areas having 14 to 20 lines of small granules on each side, 

 the interstices flat. Lateral areas scarcely elevated, having sub- 

 radiating, distant, sparse granules ; entire surface nearly smooth, 

 very minutely punctulate and striatulate under a lens. Interior : 



