DESCRIPTIONS OF GENERA AND SPECIES. 



In the following descriptions I have followed the classification adopted by Professor 

 G. 0. Sars in his recently published account of the Crustacea collected by the Norwegian 

 North Sea Expedition, which is as follows : — 



Order ISOPODA. 



Tribe I. Asellota. 



Family Asellidae. 

 „ Munnopsidas. 



Tribe II. Valvifera. 



Family Iodtheidae. 

 „ Arcturidae. 



Tribe III. Chelifera. 



Family Apseudidse. 



„ Tanaidte. 



Tribe IY. Flabellifera. 

 Family Aneeidae. 

 „ Anthuridae. 

 ,, Cymothoid33. 

 „ Serolidae. 

 ,, Sphasromidae. 



None of the new species collected by the Challenger are so divergent in structure as 

 not to fit accurately into this system, which appears to me to be in the present state of 

 our knowledge a very convenient one. The following is a complete list of the new 

 species and genera arranged under the families to which they belong. 1 



Tribe I. ASELLOTA. 



Family Asellid^;. 

 Genus Janira. 5* 

 1. Janira ahyssieola. •> 



2. 



tristani. 



Genus Stenetrium. % 



3. Stenetrium haswelli. 



Genus Iolanthe, F. E. L. 



4. Iolanthe acanthonotus. 



Genus Jmropsis. 



5. Jeeropsis marionis. 



Genus Triclwpleon. 



6. Triclwpleon ramosum. 



Genus Munna. 



7. Munna maculata. 



8. ,, pallida. 



Genus Pleurogondum. 



9. Pleurogonium albidum. 



10. „ serration. 



11. „ minutum. 



Genus Neasellus, F. E. B. 



12. Neasellus kerguelenensis. 



I have of course omitted the Serolid.'c, for which see Zool. C'hall. Exp., part xxxiii. 



