COPEPODA 



/ ^/ 



lo (ii) Right and left fifth feet of male nearly equal in length, icrminal 

 hook of right foot symmetrical. 



Diaptumiis orcgomnsis Lilljeborg iSS«;. 



The most widily <listril)Utc-«I of all North Amer- 

 ican species, and the one most likely to In- collc<.1c<l 

 in the northern part of the I'nite*! Statt-% It is 

 found from one side of the continent to the other. 

 The most noticeable characteristic is the equal 

 length of the fifth feet of the male 



Length of female, 1.5 mm. 



Length of male. 1.4 mm. 



Fig. 1176. Diapinmus orrgonemii. 

 X 193. B, fifth foot of female. 



.4. fifth fcrt u( Rulr. 

 X 200. (Uni'injl.i 



11 (10) Left fifth foot of male shorter than right 12 



12 (15) Left fifth foot reaching beyond first segment of right exopodile. . ij 



13 (14) Terminal hook of right exopodite uniangular, right endopotlilc 



equal in length to first segment of e.xopodile. 



Diaptomus rcigluirdi Marsh iSt}^. 



This has been found in only four localities, — Intermcfliate 

 Lake and Crooked Lake in northern Michigan, a lake on Beaver 

 Island in Lake Michigan, and Sodus Bay, N. V 



Length of female. 1.14 mm. 



Length of male, 1.02 mm. 



Fig. 1177. Fifth feet of male DiJ />/<'««« rrKAurrfi. X US- (Original.) 



14 (13) Terminal hook biangular, right cndopodite large, longer than \n>\ 

 segment of exopodite. 



Diaptomus mississippicnsis Marsh i.S«>4- 



The most common form of the .Southern .States; it is abundant all 

 through the states bordering on the (iulf. 



Length of female, i.-' mm. 

 Length oi male, i.i mm. 



Fig 1178 Fifth feet of male Diaptomm misustippumis. X US 



(.Orits'inal.) 



