378 PERCY SLADEN TRUST EXPEDITION 



convex upper and almost straight lower edge, bearing above a row of long, close-set, 

 subequal teeth, but toothless below ; a strong antennal, but no supraorbital or hepatic 

 spine ; eye subcylindrical with rather small cornea, which has a cup-shaped depression 

 on the outer side ; outer flagellum of antennule not deeply cleft ; antennal scale of 

 moderate breadth ; mandible without palp ; second maxilliped without podobranch, its 

 last joint mediad of preceding joint ; third maxilliped with vestige of arthrobranch, and 

 with antepenultimate joint of medium breadth ; legs rather stout, those of the second 

 pair granulate, unequal, and in one of them the chela very heavy but not very long, with 

 short, stout fingers, of which one bears a knob and the other a corresponding socket, those 

 of last three pairs with short, stout, biunguiculate dactylopodites ; submedian and inter- 

 mediate spines of telson subequal. 



Key to the species of PericlimencBus : 



I. Two teeth of rostrum stand behind orbit. Moveable finger of second leg bears 

 knob and fixed finger socket. Fringes on limbs not remarkably long. 



P. robustus Borradaile, 1915. 



II. None of rostral teeth stands behind orbit. Fixed finger of second leg bears 

 knob and moveable finger socket. Fringes of limbs very long. 



P. Jimbriatus Borradaile, 1915. 



1. (Type.) PericlimencBus robustus Borradaile, 1915 (Plate 55, fig. 20). 

 Ann. Mag. Nat. Hist. (8), xv. p. 213. 



Definition : Body rather strongly compressed ; rostrum slightly outreached by 

 antennal scale and rather more by antennular stalk, directed somewhat downwards, 

 sublanceolate, its formula -§ ; a strong antennal spine ; first joint of antennular stalk long, 

 but little expanded, second and third joints subequal ; antennal stalk reaching end 

 of second joint of antennule, scale subovate ; antepenultimate joint of third maxilliped 

 short, rather wide at base but narrowing towards penultimate joint, which nearly equals 

 it in length, last joint shorter than penultimate ; first leg outreaching antennular stalk 

 by wrist and hand, wrist longer than arm, hand stout, the fingers a little shorter than 

 the palm, a tuft of hairs on the moveable finger ; second legs unequal, the larger without 

 spines on any joint, its hand very large, stout, granulate and in parts spinulose, the 

 fingers short, abruptly hooked at the tip, the moveable one very wide, with a blunt 

 process which fits into a hollow on the fixed finger and a notch which receives a sharp 

 tooth of the fixed finger, the smaller hand with the same general characters as the 

 larger but shorter, more swollen, and with simple edges to the fingers ; the walking legs 

 moderately stout, with five spines on the propodites, and the dactylopodites short, stout, 

 bearing a sharp end-claw and a smaller claw below it ; telson as long as uropods, of 

 moderate width, narrowing somewhat towards end, which is truncate. 



In young specimens three or four of the teeth at the base of the rostrum are wanting. 



Length of the longest specimen, 14 mm. 



Amirante I., 20 — 39 fms. 



