124 



ZOOLOGY 



C 2 . Last pair of thoracic legs not shoved 



backward. 



di. Antennae, without squame ; first pair 

 of thoracic legs chelate ; cephalo- 

 thorax with 2 longitudinal lines . 

 d%. Antennae with squame. 



e\. Squame small ; antennules and 

 antennae near each other ; first 

 pair of thoracic legs very heavy 

 with great chelae; cephalo- 

 thorax with cross-suture ; gills 

 brush-like 



Thalassinidce 



Astacidce 

 (Ex. Crayfish) 



2 . Squame large ; antennae usually 

 under antennules ; first pair 

 of thoracic legs with small 

 chelae ; cephalothorax without 

 cross-suture, gills laminate 



{Shrimps and Prawns) 



2 pairs of maxillipeds resembling the 6 following 

 pairs in being bifid [suborder SchizopodaJ. 



