114 POLYPLACOPHORA. 



intermediate valves having the lateral areas extremely narrow- 

 central areas very minutely reticulated all over. Marginal ligament 

 very narrow, rufous. Length 10, breadth 6 mill. {Rochebr. in 

 Bull. Soc. Philora. de Paris. 1883-1884, p. 35). 



Chili (Gaudichaud) ; Mus. Paris. 



11. North Pacific species. 



Ch^topleura thouarsiana Rochebr. Shell ovate oblong, 

 compressed, carinated; subrufous, covered throughout with greenish 

 spots. Anterior valve 10-rayed, granulose, the granules concentric, 

 ally disposed, bordered with a bruad margin. Posterior valve small, 

 umbonated. Intermediate valves having the median areas longitudin- 

 ally sulcated, the sulci angularly arranged. Lateral areas with 

 impressed pits ["favis impressis "], laterally graniferous. Marginal 

 ligament brown, with scattered rufous sette. Length 32, breadth 14 

 mill. (Rochebr. in Bull. Soc. Philom. 1881-1882, p. 191). 



Kamchatka (Du Petit-Thouars). Rare. Paris Mus. 



This is, of course, a Mopalia. 



Chiton setosus Tilesius, Mem. Ac. St. Petersb. (1st ser.) ix, p. 

 484, 1824. Not identified. 



Chiton muricatus Tilesius, I. c, p. 483, 1. 16, f. 3. Not identified. 

 See MiddendorfF, Mai. Ross., p. 129. 



Chiton incarnatus Nuttall. Upper California. Jay's Cata- 

 logue, 3d. edit., p. 37. Name only. 



Chiton inornatus Nuttall. Sandwich Is. I. c. Undescribed. 



Chiton textilis Nuttall. Upper California. /. c. Undescribed. 



12. Species of unknown habitat. 



Chiton rugulosus Sowerby. Median part of valves longitu- 

 dinally rugulose; lateral parts closely radiated. {Sowb., Cat. Tank. 

 Coll., p. v.). Habitat unknown. 



Chiton versicolor Sowerby. Vol. XIV, pi. 27, figs. 45, 46. 



Shell oblong, scarcely carinated, subattenuated in front. Central 

 areas striated at the sides ; lateral areas radially striated, the strise 

 branching toward the edges. Margin most minutely scaly. 



Length 1 inch, breadth 5 inch. (Soivb.) 



The species is oval, oblong, rather narrower in front, the central 

 areas nearly smooth in the middle, and striated at the sides ; lateral 



