460 Mr. S. V. Wood's Catalogue of Shells from the Crag, 



Cor. Crag. Bed Crag. Mam. Crag. Becent, 



3. Chiton tenui-sculptus, n, s. 



Sutton. I I I 



4. — arcuarius, n, s. 



Sutton. I I t 



5. — angulosus, n. s. 



Sutton. 1 [ I 



I have considered these as Nov. Spec, with doubt, having been un- 

 able to procure more than four British species to compare with, and 

 all the hitherto published figures and descriptions are inadequate for 

 that purpose. In order to obtain a correct determination in the fos- 

 sil Chitons (where seldom more than detached valves are met with), 

 their degree of convexity must be ascertained, their altitude and re- 

 lative dimensions of length and breadth, the amount also of angula- 

 rity in the central valves, and the shape and magnitude of the sus- 

 tentacula, or processes at the posterior part of each, which vary in 

 all the species I have examined. 



1. Lottia virginea, Gray (var. a. Patella virginea, Muller, Z. D. Prod. 



237. var. /3. Patella conica, Jeffries. Patella equalis, Min. Con. 

 t. 139). 



Sutton. I Sutton. | | Britain. 



2. — r parvula (Patella parvula. Woodward, Geol. of Norf. t. 3. f. 1). 



I I Bramerton. | 



1. Patella vulgata, Linn.^ 



I Sutton. I I Britain. 



Only one imperfect specimen ; it differs from the common character 

 of the recent shell in having the rays slightly imbricated. 



Ord. Pleurobranchiata. 

 Cor. Crag. Bed Crag. Mam. Crag. Becent. 



1. Bulla catenata, mihi (Scaphander catenatus. Leach, Moll. p. 55. 



BuUaea angustata, Phil. Enum. Moll. Sic. p. 121. t. 7. f. 17. 

 Bulla dilatata. Wood, Illust. Mag. Nat. Hist. pi. 7). 

 Sutton. I I I Britain. 



2. — quadrata, Wood {Illust, Mag. Nat. Hist. 1839, p. 460. pi. 7. f. 1). 



„ Sutton. I I I 



3. — sculpta, mi^2(B. catenata, PFboc?,///M5^. May. iVa^.jyi*^ pi. 7.f.2). 



Sutton. I [ I 



4. — lignaria, Auct. (Illust. pi. 7. f. 4). 



Sutton. I Sutton. | | Britain. 



5. — ventrosa, Wood (Hlust. pi. 7. f. 5). 



Sutton, j I I 



6. — cylindracea. Wood (Illust. pi. 7. f. 8. Bulla convoluta, Min. 



Con. t. 464. Bulla cylindracea, Mont. Test. Brit. pi. 7. f. 2). 

 Sutton. I Sutton. | ... | Britain. 



7. — truncata, Mont. (Bulla subtruncata. Wood, Illust. pi. 7. f. 9). 



Sutton. I i I Britain. 



