184 AUSTRALIAN MALACOSTRACA. 



antennae one-third longer than the rostrum, the secondary ramus 

 rather shorter than the primary. The inferior antennae with the 

 basal scale reaching to the extremity of the rostrum, the lateral 

 deuticle one-fourth distant from the apex ; the fiagellum as 

 long as the animal. Mandibles with an anteriorly directed 

 process. [S. _B.] 



Gulf of St. Vincent, 4-j fathoms. 



Family III. ALPHEID^J. 



Rostrum usually short or obsolete. First pair of legs thicker 

 than the second. Second pair slender, elongated, with the wrist 

 annulated. Mandibles bilobed, or rarely simple, incurved, not 

 palpigerous. 



Genus Hippolyte, Leach. 



Rostrum long and latei'ally compressed, nearly always dentate, 

 immobile, prolonged backwards on the surface of the carapace 

 as a crest. Eyes prominent. Internal antennae rather short, 

 with two nagella, of which one is larger. External maxillipedes 

 slender, rather long. First pair of legs short, but stouter than 

 the rest. Second pair with the wrist multi-articulate. Abdomen 

 suddenly deflexed in the middle. Caudal appendages lanceolate, 

 ciliate on the margins. 



344. Hippolyte spinicaudus. 



Hippolyte spinicaudus, Milne-Edwards, Hist. Nat. Crust., 

 t, ii., p. 378. 



Body elongate, rostrum very long, styliform, taking origin by 

 a tooth towards the middle .of the gastric region, armed above 

 with a spine, and below with two or three small spines. Basal 

 squames of the external antennae as in H. varians (large, extend- 

 ing a little beyond the rostrum, and oval or rather truncate 

 obliquely from within outwards at the extremity). External 

 maxillipedes of moderate size, and styliform towards the extremity. 

 First pair of legs long and filiform, but not reaching the extremity 

 of the basal scale of the antennae. Those of the second pair of 

 about the same length, but thicker, and having the carpus divided 

 into three or four joints. Telson armed with six or seven pairs 

 of spines (not including those of the posterior border). \_M.-E.~] 



Australia (Mus. Paris). 



