184 MALACOZOA. GASTEROPODA. CYCLOBRANCHIATA, 



2. Chiton margindtus. Bordered Canoe-Shell. 



Shell elliptical, moderately convex, subcarinate, of eight 

 minutely dotted (shagreened) valves, of a greyish or reddish 

 colour, or variegated ; the anterior and posterior valves semi- 

 circular, quincuncially granulated, the rest nearly even, the 

 areas being but faintly defined, and having the granules dis- 

 posed in curved lines ; the marginal band also granulated, 

 coloured with alternate dusky and whitish spots, and edged 

 with minute spinelets. Length about three-fourths of an inch 

 or more, breadth nearly half an inch. 



It varies greatly in colour, being sometimes plain, grey, 

 greenish-grey, or brownish, or reddish, more frequently va- 

 riegated with numerous spots. Often the beaks are very 

 distinct, and the posterior margins of the valves somewhat 

 tuberculate, the prominences usually whitish. 



Not uncommon on the rocky coasts, at Peterhead, Port- 

 soy, Collieston, and in the Bay of Nigg. 



Found by Mr. Leslie and by Mr. Alexander Murray on the 

 coast of Gamrie and Peterhead. Plentiful in pools on the 

 Girdleness, and about the Cove. 



Chiton marginatus. Penn. Brit. Zool. iv. 71. PI. 36. f. 2. Chi- 

 ton marginatus. Mont. Test. Brit. i. Chiton marginatus. Flem. 

 Brit. Anim. 289. Cliiton marginatus. Lamk. Syst. vi. 321. 

 Ed. 2. vii. 492. 



3. Chiton cinereus. Yellow-grey Chiton. 



Shell elliptical, moderately convex, carinate, with the 

 sides sloping, and even; and the valves eight, moniliformly 

 striated ; the anterior semicircular, emarginate behind, con- 

 centrically rugose, and radiatingly striulate ; the posterior si- 

 milar, its anterior half subcarinate ; the rest narrow, carinate, 

 slightly beaked, striulate, with the striae of the anterior area 

 longitudinal, those of the two posterior areas, which are 

 elevated, radiatingly transverse ; the border narrow, minutely 

 reticulated, with the edge spinulose ; the colour yellowish- 

 grey, with the posterior areee of the valves variegated with 

 brown. Length four-twelfths, breadth two-and-a-half twelfths. 



An individual found on a star-fish, at Gamrie, in Septem- 

 ber, 1 842, by Miss Macgillivray ; others by Mr. Murray. 



Chiton cinereus. Linn. Syst. Nat. 1107. Cliiton cinereus. Mont* 

 Test. Brit, 3, Chiton cinereus. Flem. Brit. Anim. 289. 



