CHITON. 221 



local species. Fossil at Fort William (J. G. J.). Its 

 foreign distribution is entirely northern, viz. Spitz- 

 bergen, Greenland, Iceland, the Faroe Isles, Norway, 

 Sweden, and Denmark, in 10-150 f. (Torell, Konig, and 

 others) ; the coast of Russian Lapland, on the White 

 Sea (Middendorff) ; Massachusetts (Gould) ; New Eng- 

 land (Stimpson) ; and State of Maine, in the stomachs 

 of fishes caught in Casco Bay (Mighels) . 



This approaches C. cinereus nearer than any other 

 species : but it is narrower and higher, and of a uniform 

 yellowish-white colour ; it has a rather prominent ridge 

 and beaks ; the sculpture is finer, and not chain-like, but 

 irregularly disposed in a radiating and wavy manner; 

 its margin is notched ; and the granulation of the girdle 

 resembles bead-work. Spiral Foraminifera (Discorbina 

 rosacea and Truncatulina lobatula) seem fond of attach- 

 ing themselves to the girdle. The fry have dispro- 

 portionately large beaks. My finest specimen is from 

 Scalloway, and measures j^ths of an inch in length, and 

 half as much in breadth. 



It is the C. oryza of Spengler, C. aselloides of Lowe, 

 and C. sagrinatus of Couthouy. 



7. C. margina'tus * 3 Pennant. 



C. marginatum. Penn. Brit. Zool. iv. p. 71, tab. xxxvi. f. 2. C. cinereus, 

 F. & H. ii. p. 402, pi. lviii. f. 1 (as C. marginatum). 



Body oval, pale fleshcolour : mantle thin, edged with a 

 narrow border of light brown : girdle of moderate breadth, 

 usually puckered on the inner side (owing to the contraction 

 of the mantle), covered with minute close-set roundish 

 granules, which lie evenly on the surface ; it is of different 

 colours, and often variegated by alternate patches of reddish- 

 brown and yellow ; margin thickly fringed with short but con- 

 spicuous spines of a yellowish tint : head thick, transversely 

 oval : mouth round and plaited : gills from 15 to 20 on each 

 side, triangular, apparently not continued behind the head : 



* Bordered. 



