The external maxillipeds are almost without exception elongate and pediform. 



Epipodites are very often present on the first I pairs of thoracic legs, as 

 well as on the maxillipeds. 



As in the majority of Derapnds, the 1st pair of thoracic legs are usually 

 enlarged and chelate : the -\\d pair also are commonly chelate, and very often 

 tin- :>rd pair as well. 



It is usual for all the abdominal somites (telson, of course, excepted) to 

 carry a pair of well developed appendages, and it is common to find a styliform 

 ' iiilema at the base of the endopodite. 



The Macrura are here divided into two groups, characterized as follows : 



I. MACRURA CARIIHDES. Body and rostrum generally compressed: the 

 carapace does not impinge upon the epistome antero-laterally : the abdomen is 

 usually dorsally elbowed or humped : the pleura of the 1st abdominal somite are 

 seldom reduced. The antennal scale is almost always large and foliaceous so 

 as to entirely conceal the antennal peduncle. 



II. MACRURA ASTACIDES. Body and rostrum not particularly corapre.- 

 sometimes decidedly depressed: the carapace impinges on, or articulates with, or 

 is fused with the epistome antero-laterally: abdomen not humped: the pleura of 

 the 1st abdominal somite are reduced. The antennal scale may be present or 

 absent : if present, it may be foliaceous or spiniform : if foliaceous, it does not 

 conceal the terminal joint of the antennal peduncle entirely. 



MACRURA CARIDIDES, Dellaan. 



Salicoques, Milne Edwards, Hist. Nat. Crnat. II. 269, 338. 



llacroura Carides, DeHaan, Fuun. Japon. Crust, p. 1C>7. 



Caridea et Pemeidea, Dana, U. S. Expl. Exp. Crust, p. 501. 



Ctiridie, Heller, Crust. Sudl. Europ. p. 221. 



Knlimtid, lioas, Yidoiisk. Sclsk. Skr., 6 Itekke, unttirvidenskaboligog mathematiak Afd. I. 2, Kjobenhavn, 1880, 

 p. 155 : Ortmann in Bronn's Thier-Roiuh, Arthropodo, pp. 1116, et seq. 



Stenopidea, Pemeidea, et Phyllobranchiata Normalia, Spcnco Bate Challenger Cruit. Macrura, pp. 206, 210, 

 4SO. 



Stenopidea, Pemeidea, et Caridea, Stebbing, Hist. Crust, pp. 211, 213, 2'2i. 



Body generally compressed, rostrum generally compressed, integument 

 very rarely strongly calcified. Abdomen symmetrical, long, bent or humped ; 

 telson usually acute, occasionally bluntly rounded off; the pleura of the 1st 

 abdominal somite are not, or not much, reduced. 



The basal joint of the antennular peduncle usually has a spine or scale 

 ( " stylocerite " ) at the proximal end of its outer margin : the olfactory 

 are confined to the proximal end of the outer antennular flagellum. 



The antennal scale is almost always large, entirely concealing and project- 

 ing far beyond the antennal peduncle. 

 2 



