CHITON. 397 



more striking features of distinction. It is of a produced 

 oblong shape, acutely carinated, moderately beaked and 

 not particularly depressed. Its valves are shield-shaped 

 and much contracted in front, permitting the margin to 

 run up considerably between each valve. The general 

 colouring is variable, dirty-flesh colour marbled with 

 olivaceous angular lines or markings being the most 

 common ; frequently, too, it is pale greenish passing into 

 yellowish ash, and the olive-brown markings somewhat 

 clouded ; the dorsal ridges, or beak-like series of lanceolate 

 cappings, which are distinctly elevated above the granular 

 surface, are either smooth or finely striated, and occasionally 

 are of a jet black. The hinder, or external edges, are 

 but little incurved. The sculpture is precisely that of 

 fascicularis, but the grains are infinitely smaller, closer, and 

 more numerous (although the shell itself is much larger), 

 and are either subcircular or rounded oval, instead of tear- 

 shaped ; their arrangement, too, is not precisely identical, 

 as for the most part, although not united into chains, they 

 run somewhat parallel to the dorsal ridge. The margin is 

 very broad, is beset with sea-green somewhat glassy 

 hairs, and with eighteen pale tufts of crowded bristles 

 similarly disposed as in the last species. 



Specimens from the little islet of Herm, near Guernsey 

 (where the shell, which is very abundant in cavities of the 

 rocks, at low water, seems to replace fascicularis, which 

 we never met with there), measure an inch and a-half 

 in length and three-quarters of an inch in breadth, even 

 after the great contraction which they experience in drying. 

 (S. H.) Found at Tenby, by Mr. Lyons, according to 

 Brown. 



It is truly a southern species, and ranges to the Medi- 

 terranean. 



