CHITON. CANOE-SHELL. 23 



mots from each other; inside smooth, white, with often 

 't-h tinge, the margin thin and plain : teeth natti?h, 

 two in each valve, with a very remote pointed lateral one 

 in each valve on the cartilage side, ail locking into each 

 other ; the cavities of 'die primary ones very deep. 



The specimen before us of this rare and noble shell, 



taken in Dublin bay, is full four inches long, and mere 



/tree and a half wide. It has also been found near 



int's Causeway, at Belfast, in Bantry bay, ar,d at 



Abb's Head in Scotland : very rare. v. 7n. 



CHITON. CANOE-SHELL. 



Shell boat-shaped, with several valves or plates 

 disposed along the back in a transverse manner, 

 and incumbent on each other at their front margin. 



1. Chiton marginat us. Bordered CanGe-shell. 



Pennant, pi. 39. f. 2 Linn. Trans, viii. pi. 1. f. 2 

 Dorset Cat. pi. 1. f. 2 Wood, pi. 3. f. 4. 



Shell with eight valves, finely punctured like shagreen, 

 the seven hinder ones with a small ridge on the back which 

 ends in a small beak pointing forwards over the next ; the 

 margin coriaceous and coarsely serrate; inside covered 

 with a tough skin under which it is polished with the mar- 

 gin finely notched : color dusky, grey, greenish, or in- 

 clining to red, often spotted or marbled : length half an inch 

 or more ; breadth a quarter. In Scotland they appear to 

 grow of a large size, as the separate valves have been 

 found half an inch wide. 



Variety. Chiton septemvalvis. Montagu, p. 3. 



With seven valves, the five middle ones dark grey, trans- 

 versely divided, rough on the hinder part and nearly 

 smooth in front ; the beaks and the two ends rufous brovni, 

 and the margin faintly reticulate. 



Rocky coasts, on stones and shells, v. v. 



2. Chiton laevis. Smooth Canoe-shell. 

 Pennant, pi. 39. f. 3. 



Shell with eight valves, smooth or very faintly striate 

 transversely, raised and beaked on the-b&ck like the last ; 



the 



