Table I. Sub-family INACHIN^E. 

 Eyes without orbits ; the eye-stalks usually Ion- and slen.W , •«. 



The basal joint of the antennae ie extra™! "a n ™- ret ™ chle ' ° r retractile against the carapace or against ail acute post-ocular spinule or spine that 



affords no concealment. 



(in Platymaia apparently triad). 



extremely slender throughout, and is usually long. Legs slender. Rostrum either simple, or two-spined, or emarginate 



Key to the Indian Genera. 



Alliance]. Leptopodioida. Antenna? with the basal i - 

 with the merus narrower than the ischium fmrl ^ft Q , ' jai J ° , U8uaU f sub-cylindrical, or at any rate usually convex on the ventral surface, and independent. External maxillipeds 



n, ana orten with a large coarse palp, and therefore somewhat pediform in shape. 



l. Chchpeds both markedly longer and vastly stouter than the longest legs: rostrum simple and much longer than 



me carapace : post-ocular "neck" at least as long as the carapace Lambrach^us 



. Carapace of the 

 typical Oxy- 



rhynch shape,! tinct post-ocular 

 elongate - 1 r i a n - ' constrict ion, 



1. Carapace well- 

 calcified, not 

 depressed : ros- 

 trum separated 

 from the cara- 

 pace by a dis--{ 



r 



gular 



form. 



pyri 



which sometimes 

 forms a long 

 " neck " 



i. Chelipeds ne- 

 ver approaching 

 the longest legs 

 in length: ros- 

 trum bifid and 

 never approach- 

 ing the carapace ' 

 in length : post- 

 ocular neck, 

 when distinct, 

 short. 



r 



u Free joints of 

 the antennal pe- 

 duncle slender, 

 cylindrical and 

 not coarsely hir- <{ 

 sute : eye-stalks 

 almost' straight : 

 rostrui n horizon- 

 tal. 



z. 1 Eye-stalks 

 salient, but free- 

 ly moveable for- 

 wards and some- 

 times backwards: < 

 basal antennal 

 joint not reach- 

 ing to the apex 

 of the rostrum. 



fa.$ Body and ap- o. 4 Rostrum 



2 Basal anten- 

 nal joint long : 

 epistome spa- 

 cious. 



pendages very 

 spiny : some 



post-ocular spi- 

 nules: eye-stalks 

 retractile back- 

 wards, but no vcr 

 concealed. 



formed of two 

 long spines ; 

 none of the legs 

 subchelate Echinoplax. 



6.* Rostrum 

 short, bifid : last 

 pair of legs sub- 

 chelate Grypach.ei's. 



6. 3 Body and appendages smooth or 

 with very tavr spines : no post-ocu- 

 lar spine : the eye-stalks hardly 

 moveable backwards 



Ach^us. 



6.2 Basal antennal joint very short, not reaching to the 

 L front : epistome very narrow Paratymolus. 



6.1 Eye-stalks salient and rigidly immoveable : basal antennal joint project- 

 ^ ing beyond and above the apex of the rostrum Physach.eus. 



6. Free joints of the antennal peduncle short, flat, and densely hairy : eye-stalks much curved : 



rostrum somewhat depressed : a post-ocular tooth Camposcia. 



2. Carapace semi-membranous, exceedingly depressed and flat : rostrum in unbroken continuity with the carapac t : no post-ocular spine : 



the last pair of legs subdorsal iu position Oncinopus. 



II. Carapace nearly circular. [Epistome narrow ; a large post-ocular spiue against which the eye is retractile, but which affords no concealment : basal anten- 

 na! joint perfectly free, legs long, with much flattened blade-like joints : rostrum trifid.] PtATYMAIA. 



Alliance 2. INACHOIDA. Antennas with the basal joint flattened or concave on the ventral surface, and intimately fused with the surrounding parts, its antero- 

 external ancle produced to form a spine which is visible from above on either side of the rostrum. External maxillipeds with the merus as broad as or 

 broader than the ischium, and with the palp small. 



I. Rostrum simple: post-ocular spine small: basal antennal spine small or 

 moderate, 



J 1. Branchial regions upraised, and meeting across,:md thus concealing, the 

 cardiac region : 2nd pair of trunk-legs, in the adult, many times the 



II. Rostrum bifid: post-ocular spine large : basal antennal spine large... 



-C 



length of the carapace Encephaloides 



Cardiac region not encroached upon by the norma branchial regions: 2nd 



pair of trunk-legs of moderate length INACHOIDES. 



Eyes hardly retractile Apocremms. 



Eyes retractile against a strong post-ocular spine Collodes. 



