14 



Suborder III. Brachyuha. Abdomen much less well developed than the 

 cephalothoi'ax beneath which it is folded : its 6tli somite is almost always destitute 

 of appendages, but if, as is rarely the case {Dromiidea), they ai'e present, they 

 appear in a modified form as a pair of small lateral plates intercalated between the 

 6th and 7th somites. The front is joined with the epistome across the hidden 

 ophthalmic somite to form an interantennular septum. Thoracic sternum usually, 

 but not universally, broad, the last segment is fused with the others. The antenna! 

 peduncle never carries a movable exopodite. The genital ducts of the female 

 usually, but not always, open on the sternum ; those of the male sometimes do. 



