ORAL APPENDAGES OF MAHINK ISOPODA. 



71 



species of Synidotea from the Indian Ocean, and I have two new species of 

 Crabyzos from South Australia, in addition to a number of other forms from 

 tropical localities not yet worked out. 



There is no reason to suppose that the youth Pacific and Antarctic Regions 

 are any poorer in genera and species than the North Pacific and Arctic 

 Regions, although but few have yet been obtained from the former regions. 

 A careful study, now extending over some years, of the existing forms leads 

 me to the conclusion that future investigations will undoubtedly tend to link 

 together more closely the various genera of this family and the different 

 families of the Valvifera. 



As at present known the members of this suborder may conveniently be 

 placed in two groups, viz. : — 



i. ASTACILLLNEA, 110V. 



Containing the families Astacillidce, Stebbing, Chsetiliidsej Dana, 

 and Amesopodidfe, Stebbing. 

 ii. Idoteinea, nov. 



Containing the families Idoteidse, Fabricius, Pseudidotheidse, 

 Ohlin, and Holognathidse, G. M. Thomson. 





1st Maxilla. Maxillipede. 



Metasotne. 



Number of Number of 

 Spines on 1 Joints in 

 Inner Lobe. ! Palp. 



Num. 

 Segments. 



Der of 



Sutures. 





6 fi 



5 



3 



4 



5 

 5 

 3 



3-5 



3 

 



2 



1 



1 

 1 

 1 



3 

 1 

 1 



1 



! 



1 

 l 



1 



1 

 3 



q 



•J 



2* 



1 

 3 



1 

 1 



1 







3(?) 

 



3 







Mesidotea, Richardson 



3 5 



P p 



am 



Proidotea, Rac. & Sev 







3 

 3 



2 



3 or 4 

 3 

 3 

 3 



3 



3 



31.'4r. 



, 3 



5 

 5 



5 

 5 

 5 

 5 

 5 

 



4 

 4 

 4 

 4 

 4 

 4 



3 



Pentidotea, Richardson 





Cleantiella, Richardson 





Glyptidotea, Stebbing 





Crabyzos, Speuce Bate 



Idotea, Fabricius 





Colidotea, Richardson 



Eusymmerus, Richardson 



JBrichsonella, Benedict 





Edotia, Guerin-Mtin 



Synidotea, Harger 



2 











* The second suture is very small in some species, scarcely visible on the dorsal .-ide. 



