220 CHITONID^. 



ridge^ beaks^ and thicker coating of gi-annles 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.islandicus of Gmelin 

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

 not of BroTvn) , and C. Scoticiis of the same author ; the 

 variety is C. onyx of Spengler. 



6. C. ALBUs "^j Lmne. 



a alhns, Linn. S. N. p. 1107 ; F. & H. ii. p. 405, pi. Ixii. 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 

 wa\'y lines which converge towards the beaks ; there are also 

 in adult specimens a few darker marks of growth in each 

 plate : riJc/e sharp and conspicuous : colour yellowish-white ; 

 beahs 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 shght 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, ^^e Gordon) ; Buchan, Aberdeen- 

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

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



* White. 



