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 magnd, 



longitudinaliter et irregidariter striatd ; striis rugose granulatis ; areis later alibm parvis 

 et granulatis ; ceramo ultimo magno, umbone subcentrali ; apophysibus 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 propor- 

 tion 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. 105) appear to be concentrically 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. lavis, but it is differently ornamented, 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 (?). Payr. Tab. XX, fig. 11, a c. 



CHITON RISSOI. Payr. Cat. des Annelid, et des Moll, de 1'ile de Corse, p. 87, pi. 3, fig. 4-5, 1826. 

 ARCUARIUS. 8. Wood. Catalogue 1842. 



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



area dorsali longitudinaliter striatd; striis minute granulatis; areis later alibus transversim 

 striatis, striis radiantibus, granulatis ; apophysibus 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 linearly arranged, 



