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or more of its borders. To form the operculum the two wrists and hands — 

 whose inner edge is quite straight — are in close apposition, and the three 

 corresponding joints of the 2nd pair of legs are curved so as to make close 

 contact with the convex outer edge of the wrist and hand. The 3rd pair 

 of legs resemble the 2nd in all respects, except that they are slenderer and 

 have their upper (anterior) facets less well defined on the inner edge, and 

 narrower : they form a support to the operculum though concealed behind it. 



The fingers of the chelipeds are short and blunt, and move in an almost 

 perpendicular plane, 



The 4th pair of legs are broadly subcheliform and the 5th pair cheliform : 

 on the outer side of both, near the tip, as also in the same position on both 

 rami of the tail-fan, is the usual patch of imbricating corneous granules. 



In the male there are no abdominal appendages except those of the 

 tail-fan, which are quite symmetrical, as also — or nearly so — is the telson. 

 In the female besides these, there are 4 unequaliy-biramous appendages on 

 the left side. 



Milne Edwards and Bouvier describe the gills (which are phyllobranchiae) 

 as 14 in number on either side, a pleurobranch being present on somite XIV, 

 as in Pagurus ; but of the 2 arthrobranchise of the external maxillipeds one is 

 a rudiment and the other is non-plumose. 



Species of this genus have been found in the Gulf of Mexico and 

 Caribbean Sea (30 to 130 fathoms) ; off Cape Verde Islands and off the west 

 coast of equatorial Africa ; in Indian Seas (to 32 fathoms); off the coast of 

 S. Australia ; and off the Gulf of Panama (66 fathoms). Of the Indian species 

 one is hardly distinguishable from a species from Cape Verde Islands, this being 

 only one of the numerous correspondences between the sub-littoral fauna of 

 Indian Seas and that of the Atlantic approaches of the Mediterranean. 



I. Cancellus investigatoris, n. sp. Plate V , fig. 8. 



I have compared the single specimen representing this species with a specimen of C. 

 parjaiti, Edw. and Bouv., in the British Museum, and 1 find that the difference between the 

 two is extremely shght. 



Carapace suhcylindrical, its breadth in any part is more than three- 

 fourths of Its length m the middle line. Cardiac region remarkably broad 

 and short. Rostrum broadly triangular, not surpassing the antennal angles 

 of the carapace. 



Eyestalks shorter than anterior border of carapace, longer than anten- 

 nular peduncles, the eyes occupy about one-sixth of their length ; ophthalmic 

 scales small, setose, fairly well separated. 



