246 PERCY SLADEN TRUST EXPEDITION 



Differs from A. lorina in lacking a spine above the orbit, in the shorter falcate dactyli 

 of the last 2 pairs, and the partially gaping fingers. In A. lorina, the falcate dactyli are 

 half as long as their propodi, and the fingers meet throughout. 



204. Achaeus inimicus, sp. nov. (Plate 20, fig. 3). 



Mauritius, 100 — 200 fms., Sta. A 1 ; 1 $ type. 



An Achceus without a " neck," armed with slender spines including a supraorbital 

 spine, and with the last two dactyli falcate. 



Body short, high, triangular, pubescent, widening directly behind the orbits, 3 gastric 

 spines, the posterior one long, erect, the two lateral much smaller, directed obliquely 

 forward ; 2 cardiac spines, side by side, suberect, a little divergent, shorter than the 

 median gastric spine ; 2 dorsal branchial spines, one long, above the base of the first leg 

 and pointing strongly outward and a little upward ; the other small, in front of the base 

 of the last leg and directed outward, also a spinule near inner angle of region ; supraorbital 

 spine directed a little outward and forward ; below the lateral margins of the carapace are 

 5 spines partly visible in dorsal view ; 2 are hepatic, the posterior one with a bifid tip ; 2 

 are branchial, while the middle spine is on the pteiygostomian region. Rostral teeth 

 ending in short, blunt spines, interspace rounded, median furrow extending back to 

 posterior margin of orbit. A few spinules on anterior surface of eye-stalk, a tubercle above 

 at extremity. 



The basal joint of the antenna is spinulous, with the two distal spines larger. The 

 surface of maxillipeds and abdomen is roughened with spinules. Chelipeds rather slender, 

 furnished with straight hairs and spinules along the margins of their inner surface, 2 long 

 spines on inner edge of wrist ; fingers as long as palm, edges crenulate, meeting. Legs of 

 moderate length (first one missing) ; dactyli long in relation to propodi. 

 Dimensions of $ in mm. : 



C. 1. 5-4. 



C. b. (exclusive of spines) 3 "4. 



R. 1. (from front edge of orbit) "5. 



Antenna, free portion, 2. 



H. 1. 1-4. 



H. b. -8. 



W. L. 2. 14 ; merop. 1. 4 ; carp. 1. 2'3 ; prop. 1. 3'8 ; dact. 1. 27. 



W. L. 3. 12 ; merop. 1. 3'2 ; carp. 1. 2 "4 ; prop. 1. 3 ; dact. 1. 2'1. 



W. L. 4. 10 ; merop. 1. 3 ; carp. 1. 2*2 ; prop. 1. 27 ; dact. 1. 17. 



This species is quite unlike any hitherto described ; its spines distinguish it readily 

 from all but A. spinosus Miers, which has an elongated " neck," and no spines on the wrist. 



205. Achceus cadelli Alcock. 



AchcBUs cadelli Alcock (1), p. 171, pi. 5, fig. 1. 



Amirante, 28 fms., Sta. E 6 ; 1 £, with the anterior part of the body, including the 

 orbits, absent. Carapace, 27 mm. wide. 



The species is remarkable for the great slenderness of its legs and the similarity of the 

 four pairs of dactyli. The immovable finger of the chela has a large tooth at its proximal 

 third, while the movable finger has two or three teeth not so large, situated near the palm. 



