1910." 



AND INVERTEBRATES OF ST. HELENA. 



121 



gigantea. I was at first struck with the narrowness of the shell 

 opening in the Cassis and wondered how the crab could protrude 

 its head through it ; I found that the anterior part of the crab 

 was much flattened, and this seemed to be an adaptation to the 

 narrow opening of the shell ; but the species occurs also in the 



Text-fig. 6. 



Fa gurus imperator. 



other shells mentioned which have large rounded openings. The 

 species is common enough at St. Helena, but has not been found 

 anywhere else, and has not previously been figured. Melliss 

 mentions only one hermit-crab in his book on the island under 

 the name Pagurus be?-nhardus, a species which certainly does not 

 occur there. 



Pagurus arrosor. 



Cancer arrosor Herbst, Krabben und Krebse, ii. Supp. 1794, 

 p. 170, pi. xliii. fig. 1. 



Pagurus striatus Latr. Hist. Nat. Crust, et Insectes, v. p. 163. 



Pagurus arrosor A. Milne-Edwards & Bouvier, Exp. Travailleur 

 & Talisman, Crust. Decap. pt. i. p. 178, 1900; Alcock, Cat. Crust. 

 Indian Mus. pt. ii. fasc. i. Pagurides, p. 168, 1905. 



This species, in marked contrast to the preceding, has an almost 



