186 MOLLUSCA FROM THE CRAG. 



2. Chiton strigillatus. S. Wood. Tab. XX, fig. 10, a — b. 



Chiton strigillatus. S. Wood. Catalogue, 1842. 



C. Testa (?), ceramis dorsalibus, angulatis, subcarinatis ; area dorsali magna, 



longitudinaliter et irregulariter striata; striis rugose granulatis ; areis later alibus parvis 

 et granulatis ; ceramo ultimo magno, umbone subcentrali ; ajjophgsibus magnis convexis. 



Shell (?), central valves angular and subcarinate, with a large dorsal area 



longitudinally striated ; striae rather irregular, diverging and roughly granulate ; 

 lateral area small and granular ; posterior or final valve large, with a large dorsal 

 area, and nearly central umbo ; terminal area of this valve granular, not striated. 



Angular divergence of dorsal valve, 95°. 



Locality. Cor. Crag, Sutton. 



The valve figured at fig. 10 a is probably the penultimate one ; it is long in 

 proportion to its breadth, measuring about three fourths of the width of one side, 

 that is, from the dorsal angle to the lateral edge. It is narrower towards the sides, 

 with large projecting apophyses, convex or rather angular outwards. The dorsal 

 area of this valve is covered with linearly arranged granular striae, which diverge 

 and curve, and increase in number, or present an intermediate one about midway. 

 The granules in the terminal area of the final valve (fig. 10 b) appear to be concen- 

 trically arranged, though not in perfect regularity. In this valve the umbo is 

 nearly as far from the anterior margin as it is from the extreme and terminal edge, 

 giving it a subcircular form, the longer axis being in a lateral direction. It appears, 

 in the form of the valves, to be somewhat like Ch. Icevis, but it is differently orna- 

 mented, and I know of no recent species, with a final valve, so circular. The 

 granular striae resemble those of Ch. cinereus, but the valves in that species are much 

 broader in proportion to the length. The granules appear to be hollow, as an 

 opening is left in them where the surface is worn. 



Not being able to identify this shell with any species I was acquainted with, a 

 new name was provisionally given to it in my Catalogue, and this name has been 

 retained for the present, and such a description given as the imperfect materials 

 will admit of, which may, perhaps, at some future time, assist a conchologist better 

 acquainted with this genus than I am in the correct determination of the species. 



3. Chiton Rissoi (?). Pagr. Tab. XX, fig. 11, a — c. 



Chiton rissoi. Payr. Cat. des Annelid, et des Moll, de l'ile de Corse, p. 87, pi. 3, fig. 4-5, 1826. 

 — arcuarius. S. Wood. Catalogue 1842. 



C. Testa (?), ceramis dorsalibus, brevibus, convexis, fornicatis, non carinatis ; 



area dorsali longitudinaliter striata; striis minute granulatis ; areis lateralibus transversim 

 striatis, striis r adiantib us, granulatis ; apophgsibus subangulatis et prominentibus. 



Shell (?) with arched valves, and an indistinct, almost invisible, carina, 



covered with granular striae ; the dorsal area has the striae longitudinally or 



