1895.] A Alcock — Carcinological Fanna of India. 161 



always isolated, cupped post-ocular process into "which the eye is 

 retractile, hut never to such an extent as to completely conceal the 

 cornea from dorsal — still less from ventral — view; there is almost 

 always also a distinct supraocular eave, which is sometimes produced 

 forwards as a spine : the eyestalks are short. The hasal antennal joint 

 is broad ; its antero- external angle is generally produced forwards, as a 

 spine or tooth. The external maxillipeds have the merus as broad as 

 the ischium. 



Alliance 1. Pisoida. Post-ocular cup distinctly isolated from the 

 supra-ocular eave by a gap or fissure. 



Alliance. 2. Lissoida. Post-ocular cup in the closest contact with 

 the supra-ocular eave, a suture only intervening. 



Sub-family IV. Maiinse. Eyes either (1) with orbits, which may 

 be incomplete or complete, but are always complete enough to entirely 

 conceal the fully retracted cornea from dorsal view ; or (2) but par- 

 tially protected by a huge horn-like or antler-like supra-ocular spine, 

 or by a large jagged post-ocular tooth (Paramicippa tuburculosa, Edw.), 

 or by both. The eyestalks are usually long. 



The orbit, when present, is formed in one of two ways ; there is 

 always an arched — often very strongly arched — supra-ocular eave, and 

 a prominent post-ocular spine ; and either (1 ) the interval between the 

 eave and the spine is filled by another spine, in which case the roof 

 of the orbit, though fissured, is fairly complete ; or (2) the supra- 

 ocular eave and the post-ocular spine are in contact with one another 

 above, and below with a process of the basal antennal joint, in which 

 case the orbit has not only a complete or nearly complete roof, but a 

 complete or nearly complete floor also. 



The basal antennal joint is always very broad, and is either very 

 extensively produced outwards to aid in forming the floor of the orbit, 

 or is armed distally with one or two large spines. 



The external maxillipeds have the merus at least as wide as the 

 ischium. 



Alliance 1. Maioida. The orbit is formed (J) by a supra-ocular 

 hood, the postero-external angle of which is often produced as a spine, 

 (2) by a sharp post-ocular tooth, and (3) by a spine intercalated between 

 the two. Basal antennal joint broad, but not specially produced to 

 form a floor to the orbit ; usually armed at both its anterior angles with 

 a strong spine. 



Alliance 2. Stenocionopoida. There is no true orbit ; but either a 

 huge, outstanding, often more or less hollowed, horn-like or antler-like 

 supra-ocular spine, or a postocular tooth, or both. The basal antennal 



