NO. 1350. NATURAL HISTORY OF THE ISOPODA— RICHARDSON. 3 



a Legs of the first pair clie-liforiii. Uropoda terminal. I'lcopoda, when present, 



exchisively natatory I. Chelifera or Tanaioiuea. 



a^ Legs of the first pair not eheliforni. 

 b [Jropoda lateral. 

 (• Uropoda forming together with the terminal segment of the abdomen a candal 

 fan. Pleopodaforthemostpartnatatory.il. FLABELLiFEUAor Cymothoidea. 

 c^ Uropoda valve-like, inflexed, arching over the pleopoda which to a great 



extent are branchial III. Valvifera or Idoteoidea. 



b^ Uropoda terminal or infero-lateral. 

 c Uropoda infero-lateral. Outer branch of the second and following pairs of 



pleopoda two-jointed IV. Phreatoicoidea. 



c' Uropoda terminal. Outer branch of the pleopoda never two-jointed. 

 d Free forms. 

 c Pleopoda exclusively branchial, generally covered by a thin ojiercular 



plate (the modified first pair) V. Asellota or Aselloidea 



e^ Pleopoda fitted for air-breathing YI. Oniscoidea. 



d^ Parasitic forms. Pleopoda and uropoda sometimes absent. When present 

 exclusively branchial, and not covered by any operculum. 



VII. Epicaridea or Bopyroidea. 



The following' list incliide.s the numerous families which are com- 

 pvi.sod under these seven tribes: 



I. Chelifera or Tanaioidea.« 



1. Apseudidse. 



2. Tanaidje. 



II. Flabellipera or Cymothoidea.* 



1. Anthuridse. 



2. Gnathiidpe. 



3. Cirolanidae. 



4. Corallanidse. 



5. Alcironidse. 



6. Barybrotidse. 



7. ^gidfe. 



8. Bathynomidse. 



9. Cymothoidae. 



10. Serolidic. 



11. Sphieromida'. 



12. Limnoriidee. 



III. Valvifera or Idoteoidea.« 



1. Arcturidte. 



2. Idoteida;. 



3. Cha^tiliidse. 



IV. Phreatoicoidea. 



1. Phreatoicidtc. 

 V. Asellota or Aselloidea. « 



1. Asellidie. 



2. Janiridfe. 



3. ]Munnida>. 



4. DesmosomidjB. 



5. Munnopsid.'e. 



"The second name given above for the tribe or superfamily was suggested by 

 Dr. Theodore (iill in order that the nomenclature might be more miiform. 



