Vol. XVIII, pp. 203-204 September 2, 1905 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



A NEW CHITON FROM THE NEW ENGLAND COAST. 

 BY WILLIAM HEALEY DALL. 



Mr. Dwight Blaney of Boston, summering at Bar Harbor, 

 Maine, has interested himself in the marine invertebrates and 

 engaged energetically in dredging. Among some mollusks sent 

 to the writer for examination was a handsome chiton which, 

 after careful study and comparison with American and North 

 European species, appears to be undescribed. 



The numljcr of species of chiton on the New England coast 

 is very small and, with the exception of one deep-sea species, 

 none has been described during the last quarter century. It is 

 therefore exceptionally interesting to know of the presence of a 

 new species in this district. The species is somewhat interme- 

 diate in its characters between Tonicella and Trachydermon, with 

 a leaning toward the former, and seems most nearly related to 

 T. marmorea Fabricius, from which, however, it is abundantly 

 distinct. 



Tonicella blaneyi h]). nov. 



Shell of a deep rose-color, with fine white lineations and reticular mark- 

 ings ; girdle brown, apparent!}' naked, but exhibiting under higli magnifi- 

 cation a microscopic granulation with a row of small spinules at the extreme 

 edge, as in T. mnrmorea ; the coloration of tlie valves outside, in the type 

 specimen is fairly uniform but probably more or less variable among indi- 

 viduals ; the valves inside are of a deep rose-pink, paler toward the edges ; 

 surface minutely more or less quincuncially punctate, but this is visible 

 only when magnified ; the sculi)ture consists of (on the midvalves usually 

 :i7— Proc. Bioi.. Soc. Wash., Vol. XVIII, 1905. (203) 



