1 64 DR BAIRD ON ENTOMOSTRACA. 



generally of four, and abdomen of six, segments ; foot-jaws two 

 pairs, generally small ; legs about five pairs. One eye. 



Genus ist. — Cyclops — Muller. 



Foot-jaws large and strong, branched; antennules simple. 

 Ovaries double. 



Sp. 1st. — C. quadricomis, Muller. Zool. Dan. prod. — Ento- 

 most. Monoculus quadricomis, Linn.y Jurine. Cyclops vulga- 

 ris, Desmarest, M. Edwards. 



Hah. Common in all ponds and ditches throughout the county. 



Genus 2d. — Ctclopsina — M. Edwards. 



Foot-jaws of considerable magnitude ; simple ; antennules two- 

 branched ; ovaries double. 



Sp. 1st. — C. castor — ^Monoculus castor, Jurine* Cyclops 

 coBruleus, rubens, and lacinulatus, Muller. Cyclops castor, Des- 

 marest. Hah. Dunglass pond ; Yetholm Loch. 



Genus Zd. — Canthocarpus. — TFesftfooc?. 



Foot-jaws small, simple. Antennules simple. Ovary single. 



Sp. 1st. — C. minutus — Cyclops minutus, Muler. Entomost. 

 Monoculus staphylinus, Jurine. Cyclops staphylinus, Desmarest. 

 Hah, Pools and ditches, common throughout the district. 



Sp. 2d. — C. Stromii — Cyclops Stromii, jBairc?, Mag. Zool. and 

 Bot. Cyclops brevicomis, Baird. Trans. Berw. Nat. Club. 

 Hah. In pools on sea-shore, amongst corallines, &c. At Cock- 

 bumspath and Berwick Bay. 



Sp. 3d. — C. furcatus — Cyclops furcatus, Baird. Mag. Zool. 

 and Bot. Cyclopsina furcatus, M. Edwards. Hah. Berwick 

 Bay. 



Sp. 4th. — C. minuticornis — Cyclops minuticornis, Muller. 

 Entomost. Cyclops incrmis ? Tilesius. Hah. Berwick Bay. 



Genus 4M. — Arpacticus — M. Edwards, 

 Foot-jaws possessing strong chcliform hands ; antennules simple. 



Ovary single. 



Sp. 1st. — A. chelifer — Cyclops chelifer, Muller. Entomost. 



Cyclops Johnstoni, Baird, Trans. Berw. Nat. Club. Cycloj s 



♦ Hist, des Monoc, 50, t. 4, 6, 6. 



