192 



which are not serrated though there are 2 or 3 spines on the outer border of 

 the exopodite. 



The eyes form a colourless flange to the end of the short fixed eyestalks. 



In the antennular peduncle the basal joint is the longest and has its proxi- 

 mal end expanded and armed externally with 2 spinules. 



In the antennal peduncle the scaphocerite, which is shorter than the stylo- 

 cerite, hardly reaches a fourth of the way along the penultimate joint. 



The external maxillipeds reach slightly beyond the end of the antennular 

 peduncle ; the ischium is elegantly dentated and the merus is spinose along the 

 inner border. 



In the female the large chelipeds are just over half the total length of the 

 body, much more than two-fifths of their length being contributed by the hand : 

 the lower border of the ischium and merus and the upper border of the palm and 

 of the distal half of the merus are spinose ; a salient serrulate ridge runs along 

 the lower border of the outer surface of the palm and fixed finger, and there are 

 some scattered miliary granules on both surfaces of the palm : the palm is a 

 little longer than the carpus and a little shorter than the fingers, the fingers are 

 slender and sharp and do not meet at base, the cutting-edge of the fixed finger 

 is finely serrulate : there are a few setae on the fingers and palm. 



The 2nd pair of chelipeds are a little stouter and shorter than the three last 

 pairs of legs : the latter have a long propodite and a slender acute dactylus. 



Colour in life ; abdomen light brown, carapace very pale pink fading to 

 slate-colour on the sides. 



Length of carapace and rostrum measured in the middle line 22 millim., of 

 abdomen 32*5 millim. 



From the Arabian Sea, off the coast of Sind, 947 fathoms. 

 Regd. Nos. -=p (Types of the species). 



112. Colocaris (CalastaCUS) felix, Alcock and Anderson. 



Calastacns felix, Alcock and Anderson, Ann. Mag. Nat. Hist., April 1899, p. 287. 



ILLCSTRATIONS OF THE ZOOLOGY OF THE INVESTIGATOR, CBUSTACEA, Pr.ATE XLII. FtG. 3. 



Carapace (rostrum included), measured in the middle line, as long as the 

 first 6 abdominal somites ; its surface is pitted, and lank antrorse setae, which 

 are very distinct on the gastric and cardiac regions, spring from the pits ; the 

 cervical groove is distinct, but the branchial grooves are indistinct. 



The rostrum reaches to the end of the 2nd joint of the antennular peduncle ; 

 in addition to the 2 spines on each of its lateral prolongations on to the gastric 

 region, there are 2 large spines on each of its edges near the tip. 



