Chiton. MOLLUSCA. BRANCHIFERA. 289 



crinitus of Pennant, Brit. Zool. iv. 71- t. xxxvi. f. 1., which he describes 

 " with seven valves ; thick set with short hairs ; |ths of an inch long," as 

 inhabiting the sea near Aberdeen, is no other than this species. In the figure 

 may be traced the tufts and the central striated ridge ; characters unnoticed 

 in the description, — and, it may be added, that the figure given by Maton and 

 Kackett of the Chiton fascicularis, Linn. Trans, viii. t. i. f. 1., bears no remote 

 resemblance to the one by Pennant, now referred to. 



* Marginal band rough. 



159. C. marginatus. — Shell with a central ridge, regularly 



shagreened. 



Perm. Brit. Zool. iv. 71- t. xxxvi. f. 2. Mont. Test. Brit. i. Maton and 

 Backett, Linn. Trans, viii. 21. t. i. f. 2. Flem. Edin. Encyc. vi. 102. 



C. cinereus, Lowe, Zool. Journ. vol. ii. p. 99 On stones about low 



water-mark, common. 



Length about fths of an inch, breadth |ths. Colour greyish or reddish, 

 sometimes freckled. Anteal and retral valves with about ten notches on the 

 margin of each, on the lower edge ; the intervening valves with only one notch 

 on each side, the termination of a flexure in the shell, which extends ob- 

 liquely to the back of the ridge, and divides each side of the valve into two 

 triangular compartments, the retroJateral ones being always more elevated. 

 In the last valve the lines of growth are elliptical and entire. The margin 

 of the shell, around, is a little depressed. Body rough, dusky brown, some- 

 times freckled with white, with a spinous margin. Branchiae about twenty 

 on each side — I possess a variety of this shell, which I found under a stone 

 at Newhaven in 1811, with only six valves. Is the Chiton Asselloides of Mr 

 Lowe, Zool. Journ. vol. ii. 100. t. v. f. 5., any thing else than an indistinctly 

 marked variety of the present species. The fringe being short and indis- 

 tinct, might lead to the suspicion that it was the same as C. marmoreus of Fa- 

 bricius, though that species is probably not distinct from C. marginatus. 



160. C. rube?'. — Smooth, glossy, marked by distinct lines of 

 growth. 



Patella articulata cymbiformis, Wallace, Ork. 41 C. ruber. Linn. Svst. 



Nat. i. 1107.— C. laevis, Penn. Brit. Zool. iv. 72 — C. ruber. Flem. 



Edin. Encyc. viii. 102. Lowe, Zool. Journ. ii. 101. t. v. f. 2 On 



stones at low water-mark, common. 



Length about half an inch, breadth a quarter. Colour reddish, mottled 

 or striped with brown and white. This is more sharply arched than the pre- 

 ceding, producing a higher dorsal ridge ; valves with blunt beaks, perfectly 

 smooth, except by the lines of growth, with marginal notches nearly like the 

 last ; border broad, striped brown and white, with a nearly entire margin. — 

 This species is very common in Orkney and Zetland : we have found it like- 

 wise in abundance on the shores of Loch Broom, whence Pennant's specimens 

 were obtained — Mr Lowe has found it on the Yorkshire coast. 



161. C, cinereus. — Valves short, depressed, moniliformly 

 striated. 



Linn. Syst. Nat. i. 1107. Mont. Test. Brit. 3. Flem. Edin. Encyc. vii. 

 102 — C. Assellus, Lowe, Zool. Journ. ii. 101. t. v. f. 3. — On stones 

 and old shells at low water, not uncommon. 



Length about half an inch, breadth about a quarter. Colour greyish, with 

 dusky stripes ; valves little raised in the middle, and but slight beaked ; 

 markings of growth indistinct ; striae longitudinal on the anteal, and diago- 

 nal on the retral compartment; under margin of the valves granulated, not 

 notched. Border narrow, with an indistinct fringe. 



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