148 DR BAIRD ON ENTOMOSTRACA. 



FAMILY 1.— DAPHNID^. 

 Two pairs of antennae ; superior very small ; inferior large and 

 branched, and used as organs of locomotion. Five pairs of feet. 

 Head prolonged into a more or less blunt beak. Eye single, large. 

 Intestine straight. 



Genus ls<.— DaphniA — Muller. 



Inferior antennas large and branched, one branch having four, 

 the other three articulations. 



Sp. 1st. — D. pulex — Daphne pulex, Mull. Zool. Dan. prod. 

 Daphnia pennata, Mull. Entomost. Daphnia pulex, Straus. 

 Monoculus pulex, Jurine. Hah. common in ponds and ditches, 

 &c., in all parts of Berwickshire. 



Sp. 2d. — D. vetula — Daphne vetula, Mull. Zool. Dan. pro- 

 drom. Daphnia sima, Mull. Entomost. Daphnia vetula, 

 Straus. Monoculus sima, Jurine. Hah. common in ponds and 

 ditches in Berwickshire. 



Sp. 3d. — D. reticulata — ^Monoculus reticulatus, Jurine.* 

 Daphnia quadrangula ? Muller. Entomost. Hah. ditch near 

 Berwick. 



Sp. 4th. — ^D. rotunda, Straus. Mem. du Mus. d'Hist. Nat., 

 V. t. 29, f. 27-28. 



Sp. 5th. — D. brachiata — Monoculus brachiatus, Jurine. Hist, 

 de Monoc, &c., t. 12, f. 3-4. 



Sp. 6th. — ^D. mucronata — Daphnia mucronata, Mull. Ento- 

 most. Monoc. bispinosus, De Geer. Daphnia bispinosa, Koch, 

 Deutsch. Crust., H. 8, t. 1. 



Genus 2d. — SiDA — Straus. 



Inferior antennse, large and two branched, one branch having 

 three, and the other two articulations. 



Sp. 1st. — Sida crystallina, Straus. Mem. du Mus. v. — Daph- 

 hia crystallina, Muller, Monoculus elongatus, De Geer. 



FAMILY 2.— BOSMINIDJE. 



Superior antennsB pendulous from the beak, and longer than in 

 preceding family. Inferior large, two branched. 



♦ Hist, des Monoc., Ac, 139, t. 14, f. 3-4. 



