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calcified in front of the cervical groove, almost coriaceous or membranous behind 

 it, tho rostral prolongation broad and inconspicuous. 



Abdomen coiled in a spiral, for the most part soft and submembranons, tlio 

 first two terga are, however, fairly well calcified, as are also the last tergnm 

 and the telson. The tucked-in caudal swimmerets are asymmetrical, those of 

 the left side being larger than those on the right: on both sides the exopodite 

 and endopodite are somewhat claw-like, and have on their dorsal surface a 

 pavement of sharp beady granules. 



The ophthalmic scales, -which are sharp and conspicuous, are separated by a 

 considerable interval : the eyestalks are usually long and slender. 



The antennular peduncle is nearly as long as the carapace : the upper 

 antennular flagellum, which is the longer, is not half the length of the peduncle. 

 The acicle of the antennal peduncle is long and slender. 



The mandibles have a prominent and trenchant incisor process separated 

 from the small receding molar process by a groove, and an incurved 3 -jointed 

 palp. 



The 1st and 2nd maxillas have the coxopodite, basipodite, and endopodite 

 well developed : in the 1st maxillas the coxopodite is recedent, in the 2nd maxilla 

 the coxopodite and basipodite are deeply cleft and the scaphognathite is sub- 

 acutely produced. 



All 3 pairs of maxillipeds have strong exopodites : those of the 1st maxilli- 

 peds are simple non-flagellate falciform plates : those of the 2nd and 3rd maxilli- 

 peds are slender and end in long flagella: only the 1st pair of maxillipeds have 

 an epipodite, and there are no epipodites to any of the thoracic legs. The 2nd 

 and 3rd (external) maxillipeds are simple and 7-jointed, but without any move- 

 ment between the basis and ischium : the external maxillipeds are separated at 

 base by a considerable interval. 



The thoracic legs of the 1st pair are remarkably unequal, the right being 

 much larger than the left : the fingers open in an oblique plane and have 

 calcareous or slightly corneous tips. 



The legs of the 2nd and 3rd pairs are of remarkable length, and end in 

 very long somewhat twisted dactyli : those of the 4th and 5th pairs are extremely 

 short, and end in little claw-like dactyli, the 4th pair being subcheliform and the 

 5th pair minutely cheliform. 



In the male the first two abdominal somites have each a pair of uniramous 

 appendages modified for copulation, and the 3rd-5th somites have, on the left 

 side only, each a biramous appendage of which the inner ramus is rudimentnrv. 

 In the female the 1st abdominal somite is destitute of appendages, and the 2nd- 

 5th have, on the left side only, each a biramous appendage. 



The gills are 11 on either side, disposed as follows : a pair of arthrobranchs 

 28 



