214 



telson is not divided by a transverse suture, and is not so long as the caudal 

 swimmerets. 



The ophthalmic scales are contiguous and the eyes are small and pale. 



The external maxillipeds are not chelate, though they are in close contact 

 with one another at base. 



The thoracic legs of the 1st pair, though symmetrical and equal and more 

 massive than any of the other legs, have a carpus of ordinary form and a sub- 

 cylindrical hand not modified to form a stopper. 



In the female the abdominal appendages of the 1st pair are slender and 

 uniramous, and those of the 2nd-5th pairs are slender and biramous with one 

 ramus rudimentary: in the male all, from the 1st to the 5th, are uniramous and 

 only those of the 2nd pair are of any size. 



The branchial formula is exactly the same as that of Pylocheles, but the 

 arthrobranchise of somite IX (external maxillipeds) are mere non-plumose fleshy 

 lobes, there are thus only 12 functional branchiae on either side, namely, 4 pairs 

 of arthrobranchia? (on somites X.-XIIL), and 4 pleurobranchiae (on somites 

 XI.-XIV.). 



From Mixtopagurus it differs in having the abdomen softer and the ophthal- 

 mic scales in contiguity, also in having only 12 functional branchiae on either side. 



2. Parapylocheles seorplo, Alcock. 



Pylocheles Scorpio, Alcock, Ann. Mag. Nat. Hist., Mnrch, 1894, p. 244. 



ILLCSTRATIONS OF THE ZOOLOGY OF THE INVESTIGATOE, CRUSTACEA, PLATE IX. FlG. 7. 



Body long and slender, with a wasp-like constriction between the cephalo- 

 thorax and abdomen, cephalothorax subcylindrical. Carapace half the length of 

 the abdomen, strongly calcified smooth and polished in front of the cervical 

 groove, behind which it is less strongly calcified dorsally and membranous 

 laterally : the frontal margin is much excavated behind the eyestalks, between 

 which a small rostrum projects, and on the outer angle of either orbital notch is 

 a pair of spinules. 



All the abdominal terga are distinct and symmetrical: the 1st which is 

 extremely small, and the 6th which is suboval, are strongly calcified ; but the 

 2nd— 5th, Avhich are subrectangular plates, are feebly calcified, except a patch in 

 the middle of the posterior border of the 5th : their edges are setose, as also is 

 the surface of the 6th and of the telson. The caudal swimmerets are perfectly 

 symmetrical; the outer part of the dorsal surface of both endopodite and 

 exopodite has a pavement of small setose bead-like tubercles. 



The eyestalks, which are about a third the length of the carapace, taper 

 from a broadish base up to a small pale eye : their dorsal surface is finely 

 serrated and setose towards the edges. 



