1899.] A. Alcock — Carcinological Fauna of India. 37 



Very like N, gladiator but easily distinguished by the following 

 characters : — 



(1) the carapace is longer and narrower, its length being three- 

 fourths its breadth without the great lateral spines; and its sub- 

 regional convexities are in much stronger relief and much better 

 defined : 



(2) the median frontal teeth are smaller and less prominent, and 

 the outer angle of the middle lobe of the supia-orbital margin is less 

 acute : 



(3) the crests of the outer surface of the palm and immobile 

 finger and of the third abdominal segment are not only more salient 

 and trenchant, but also have a curious silvery or coppery pearly sheen : 



(4) the chelipeds are shorter ; and there is a dark round spot near 

 the tip of the dactyl us of the last pair of legs. 



It is a very much smaller species ; only one of numerous egg-laden 

 females in the Indian Museum has the carapace more than 20 millira. 

 long and 30 millim. broad (including spines). Specimens of N. gla- 

 diator of this size are obviously immature. 



In the Indian Museum are 63 specimens from the Andamans, 

 Mergui (Marine Survey), Arakan coast, Ganjam coast, Ceylon, and 

 Malabar coast. Nearly half the specimens are recorded from depths of 

 18 to 33 fathoms. 



15. Neptunus (Amphitrite) argentatus var. glareosus. 



In this variety the carapace is even narrower and more elongate, 

 its subregional convexities are hardly less salient and well defined than 

 those of N. tuherctdosus, and its surface is almost free of tomentum. 

 The carina of the 3id abdominal tergum is about twice as prominent as 

 it is in the typical form, having the shape of a prominent foliaceous 

 lobe. The dorsal surface of the body and chelipeds is profusely 

 speckled. 



26 specimens, including egg-laden females, were dredged from a 

 bottom of sand and stones off the Andamans at 55 fathoms. 



36. Neptunus {Amphitrite) petreus, n. sp. 



This species differs from N, gladiator^ and approaches N. spinicarpus 

 Stimpson, in the enormous development of the spine at the inner angle 

 of the wrist. 



It will be sufficient to point out the characters that distinguish it 

 from N. gladiator, of which it may prove to be only a variety. 



The length of the carapace is nearly | tlie breadth without the 

 lateral spines. The frontal teeth are blunt and the epistome is not 



