98 AMERICAN MARINE CONCHOLOGY. 
the lateral margins, which are rounded with an elevated marginal 
line. Medial areas lozenge-shaped, with numerous elevated 
rounded dots arranged in ten or twelve series on each side of the 
carina, parallel with the longitudinal axis of the body; grayish, 
bluish, or ferruginous. 
Length 13 to 25, width 7.5 to 15 mill. 
Whole Coast. 
3. C. cINEREUS, Linneeus. Fig. 200. 
Syst. Nat., edit. xii. 1107. 1767. 
Chiton marginatus, Pennant, Brit. Zool., iv. 61, t. 36, f. 2. 1777. 
Shell small, ovate, carinate and pointed behind; surface appa- 
rently smooth, but under the lens minutely shagreened in dia- 
mond-shaped granules ; dull ashen or greenish. 
Length 12, width 7 mill. 
New England. (Hur.) 
4, C. MARMOREUS, Fabricius. Fig. 201. 
Fauna Greenlandica, 420. 1780. 
CO. fulminatus, Couthouy, Bost. Journ. Nat. Hist., ii., p. 80, t. 3, f. 19. 1888. 
Shell oblong-ovate, rather flat, color varying from bright red to 
yellowish or dark reddish-brown, with numerous fine zigzag whit- 
ish lines arranged over the whole surface, and a line of six or 
eight whitish spots alternating with dark red along the posterior 
edge of each valve; valves carinated and slightly beaked, their 
surface covered with microscopic granulations arranged in quin- 
cunx; triangular areas very indistinct; margin narrow, coriaceous, 
coated with a close, short down, alternately red and white. 
Length 17.5, width 11.3 mill. 
New England. (Hur.) 
5. C. atBus, Montagu. Fig. 202. 
Test. Brit. 4. 1803. 
Chiton aselloides, Lowe, Zool. Journ., ii. 108, t. 5, f. 3. 
Chiton sagrinatus, Couthouy, Am. Journ. Sci., xxxiv. 217. 18538. 
Shell small; valves with a small beak, minutely crenulate on their 
anterior margin, subcarinate, with minute striz ; surface minutely 
shagreened ; an obsolete diagonal ridge sometimes divides each 
side into triangular areas, but for the most part without any 
distinct boundaryg margin membranous covered with beaded 
granules; grayish-white under a pulverulent black epidermis ; 
marginal membrane ashy, with a narrow black median band, 
Length 10, width 3.7 mill. 
New England. (Hur.) 
