340 



A HISTORY OF BECENT CEUSTACEA 



SYJ^fOFSJS OF TEE 



Maxillipefls with the ' palp ' free, 

 the margins of the last two 

 joints more or less setose, never 

 furnished with hooks 



First maxillaa with the plate of 

 the third joint tolerably broad, 

 at least towards the middle 



Mandibles with the distal half 

 stout, very conspicuous, un- 

 covered, or with only the an- 

 terior margin concealed ; from 

 the base towards the middle 

 directed forwards and a, liitle 

 outwards 



Mandibles with the distal half 

 narrow, most or all of it con- 

 cealed by the upper and lower 

 lips ; from the base towards the 



, apex directed gradually inwards 



Maxillipeds with the ' palp ' em- 

 bracing the cone formed by the 

 distal parts of the mouth-organs, 

 the inner upper margin and 

 apex never setose, the apex and 

 sometimes the inner upper mar- 

 gin, at least in the males and 

 the females without eggs, being 

 furnished with outward curved 

 hooks 



First maxilloe with the plate of 

 the third joint narrow through- 

 out 



Distal parts of the mouth-organs' 

 foi-ming a cone directed some- 

 what forwards 



Secondma.xillae small, feeble, with- 

 out hooks 



Maxillipeds with the fourth and 

 fifth joints coalesced, forming a 

 very long joint 



^ Distal parts of the mouth-organs 

 forming a short subvertical cone 



Second maxillae large, elongate, 

 and proportionately broad, with 

 two apical plates furnished with 

 books 



Maxillipeds with the fourth and 

 fifth joints sometimes coalesced, 

 never forming a long joint 



