50 



GEOL. AND NAT. HIST. SURYEY OF MINNESOTA. 



Still later it became evident that two sections could readily be 

 distinguished within the genus which have since then been elevated to 

 generic rank by Claus. Both these groups agree in several charac- 

 ters, such as the following: Head distinct from the thorax, fourth 

 and fifth thoracic segments closely united, frequently only the lateral 

 or pleural portions of the latter being evident, abdomen composed of 

 four segments in the male and three in the female, antennae shorter 

 than the body, 24-(or 26 ?) jointed, right male antenna geniculate, in- 

 ner rami of swimming feet, one-or two-jointed, in the female small, in 

 the male prehensile. As restricted by Claus, the genera stand re- 

 lated as shown by the following tabular diagnosis: 



Temora. 



AnteuDai of male 24 jointed, genicu- 

 latioD between joints 18 and 19. Max- 

 illae and maxillipeds rather large. 



Fiist foot with two-jointed inner 

 ramus. 



Fifth feet one-branched, the left in 

 the male three-jointed, dactylate, right 

 two-jointed, unguiculate, in the female 

 apparently two-jointed. 



Habit, marine. 



Sp. 1. T.longicaudata 'Luhhock {=T. 

 finmarcMca Baird, etc.). Angle of last 

 abdominal segment rounded, left foot 

 of fifth pair in male three-jointed, with 

 a long, immovable process on the first 

 joint, the two remaining forming an 

 apposable clasper, antennie as long as 

 whole body. (North Sea.) 



»S!p. 2. T. armata Claus. Angle of 

 last abdominal segment produced for- 

 ward, left foot of fifth pair in the male 

 with the terminal joint expanded into 

 a plate, antennse reaching nearly to end 

 of the abdomen. (Mediterranean.) 



Sp. 3.' T. duhia Lubbock. (As iden- 

 tified by Brady.) Exactly as in T. ar- 

 mata*, save that the antennse are said 

 to be about as long as the cephalothorax. 

 (Pacific and Atlantic Oceans.) 



*The agreement is so close, eren in minute 

 details, that a varietal distinction at the utmost 

 seems demanded. See Claus, Ufber die Gallun- 

 gen Temora und Temore/lri, and Brady, Challen- 

 ger Copepoda. 



Eurytemora. 



Antenrse 24-(25?) jointed, genicula- 

 tion between joints 18 and 19. Max- 

 illae and maxillipeds quite shoit. 



First foot with Ijointed inner ra- 

 mus. 



Fifth feet one-branched, both three- 

 jointed, the left with an expanded apex, 

 the right with a strong claw, in the fe- 

 male obviously three-jointed, the pen- 

 ul ti mate segment bearing a strong spine. 



Habit sub-marine or fluviatile. 



Sp.l. E.velox{Ul\g.) Brady (=7. 

 dausii Hoek). Penultimate joint of 

 the fifth foot of female with a single 

 spine externally, caudal stylets four to 

 five times as long as wide and feebly 

 spined. (Scandinavian and North Eu- 

 ropean coasts.) 



Sp. 2. E. affinis Poppe. Last seg- 

 ment of thorax produced. Penultimate 

 segment of fifth foot in the female, with 

 two spines externally, caudal stylets 

 six to seven times as long as wide. 

 Segmentation of last joints of male an- 

 tenna3 more obvious. (Same localities 

 and rivers Rhine, Elbe, etc.) [See be- 

 low on 7'. hirundo.'l Poppe very posi- 

 tively declares 7\ dausii to be identical 

 with the T. velox of Lilljeborg, but 

 Claus explains that the male seen by 

 Lilljeborg was T. dausii. As identified 

 by Brady, in England, 7. velox evi- 

 dently corresponds to T. dausii, whhic 

 should therefore probably yield priority 

 to the older name. 



E. affinis occurs very abundantly in 

 rivers and estuaries of, as well as in the 

 Gulf of Me^iico. 



Sp. 3. E. lacusfris Poppe. Last seg- 

 ment of thorax rounded. Penultimate 

 segment of fifth foot of female with two 

 spines. Caudel stylets of female about 

 as long as broad. From fresh-water 

 lakes, Holstein, Sweden, Finland, etc. 



