220 chitonidjE. 



ridge, beaks, and thicker coating of grannies on the 

 girdle, which is broader than in that species. 



It is the C. asellus in Spengler's monograph of the 

 genus (Skr. Nat. Selsk. 1797), C.iskindicus of Gmelin 

 (from Schroter's 'Einleitung } ) , C. fuscatus of Leach (but 

 not of Brown) , and C. Scoticus of the same author ; the 

 variety is C. onyx of Spengler. 



6. C. ALBUs % Lmne. 



C. albus, Linn. S. N. p. 1107 ; F. & H. ii. p. 405, pi. kii. f. 2. 



Body narrowly oval, brownish yellow : girdle rather broad, 

 regularly and closely beaded with glittering equal-sized oval 

 granules, which have their smaller points towards the beaks 

 of the shell ; margin fringed with short spines. 



Shell rather convex : plates narrowish, solid and opaque, 

 somewhat glossy ; lateral compartments slightly raised : sculp- 

 ture, numerous and small granules, arranged in irregular and 

 wavy lines which converge towards the beaks ; there are also 

 in adult specimens a few darker marks of growth in each 

 plate : ridge sharp and conspicuous : colour yellowish-white : 

 beaks small, prominent : inside porcellanous, with sometimes 

 a bluish tinge, displaying broad leaf-like shoulders on all the 

 plates except that which covers the head : notches slight but 

 distinct, 13 on the head-plate, 11 on the tail-plate, and 2 on 

 each of the other plates (one on either side), making altogether 

 36. L. 0-35. B. 0-2. 



Habitat : Stones, old shells, and sea- weeds, from 

 low-water mark to 30 f.; Ballaugh, Isle of Man (Forbes, 

 from whom I received a specimen in 1841, with a note 

 of this locality, and named "Chiton, new sp."); west 

 coast of Scotland (R. T. Lowe and others) ; Burghead, 

 Moray Firth (Murray, fide Gordon); Buchan, Aberdeen- 

 shire (Dawson); Wick (Peach); Orkneys (Thomas); 

 Lerwick and other parts of Shetland (J. G. J.): it is a 



* White. 



