Class\ficatW7i of the Dtcapod Crustaceans. 473 



2. Second legs chelate. 



i. Both legs of tile first pair chelate. Second 



wri.sts undivided. Third joint in the 



third nmxillipeds very broad. Rostrum 



toothed Gnathophyllidae. 



ii. One leg of the first pair simple. Second 



wrists subdivided. Tliird niaxillipeds 



pediform. Rostrum not toothed .... Processidae. 

 II. Both legs of the first pair subclielate. Ros- 

 trum long or short, not com])re8sed. 



1. Second wrists subdivided. Inner lobes of 



first niaxillipeds not reduced. Rostrum 



long Glyphocrangonidae. 



2. Second wrist undivided. Inner lobes of 



first maxillipeds reduced. Rostrum short. Crangonidae. 



Key to the Tribes of the Reptantia. 



I. Third legs like first, either chelate or simple 



and subcyliudrical. Abdomen macrurous 

 (straight, symmetrical, well armoured, with 

 good pleura and strong broad tail-fin, lobes 

 on the first segment clipping the carapace). 

 Gnathobases of second maxilhe narrow. 

 Basipoditic lobes of first maxillipeds usually 

 deep. Exopodiles of niaxillipeds with lash 

 directed forwards. Gills numerous. [Last 

 thoracic segment with legs not differing 

 greatly from the rest and sternum rarely f ree. j 



1. Carapace fused at the sides to the epistome. 



Rustrum small or wanting (except Falinn- 

 rellus). Inner lobes of second maxillae 

 and first maxillipeds reduced. An o;> 

 petulix interna on some of the abdominal 

 limbs, at least in the female, but the exo- 

 podites of the last pair without sharp 

 suture. Body often depressed PALINURA, 



2. Carapace free from the epistome. Rostrum 



of good size. Inner lobes of second max- 

 illie and first maxillipeds not reduced. 

 No ajipendix intenia, but the exopodites 

 of the last abdominal limb divided by a 

 suture. B )dy subcyliudrical ASTA CURA. 



II. Third legs unlike first*, never chelate. Ab- 



domen rarely macrurous. Gnathobase of 

 .second maxillae typically broad. iJa«ipoditic 

 lobes of first maxillipeds broad but shallow, 

 their inner edge usually in a line with that of 

 the coxopodite. Exopodites of maxillipeds 

 with lash, when present, nearly always bent 

 inwards. Gills usually few. 

 1. Carajiace not fused with epistome. Last 

 thoracic sternum free, its legs differing 



* Gebicula nearly forms an exception to this. 

 Ann, d) Mag. X. Hist. Ser. 7. Vol. xix. 33 



