196 Insects, 



never seen them swim about as the animals of the genus Cypris do, 

 but when shaken out of their lurking-places into a tumbler of water, 

 they descend in gyrations until they reach the bottom, and then they 

 creep along the surface of the vessel till they reach any vegetable mat- 

 ter they can find ; upon this they creep along searching for food. In 

 this habit they differ very widely from the beautiful little insects be- 

 longing to the genus Daphnia, which, firom their long and mostly fea- 

 thered rami and branchial feet, are well fitted for swimming about. 

 In the ^Annals and Magazine of Zoology and Botany' for 1837, I de- 

 scribed four species as inhabitants of Britain. Since that time I have 

 ascertained the existence of several more, one of which I have never 

 met with but in one spot, a stagnant pool in the old St. Pancras road, 

 nearly opposite old St. Pancras church ; — a pool which, in a year or 

 two, will have changed its character from a habitat for Daphniae, to a 

 resting-place for brick houses and the residence of human beings. — 

 This species has been described and figured by Jurine in his work on 

 the Monoculi of the environs of Geneva, but has never been noticed 

 till now as an inhabitant of Great Britain. 



Legion. — Branchiopodes. 



Order. — Daphnoides or Cladoceres. 



Family. — Daphnidiens, Milne Edivards, 



Genus. — Daphnia, Muller. 

 Daphtiia brachiaia.* The length of this little creature is about 

 half a line. The shell is of an olive colour, transparent, showing the 

 stomach &c. very distinctly. It bulges out very much posteriorly, 

 giving the insect a very jolly appearance, and is ciliated anteriorly. 

 The main stalk of the rami is very large and fleshy looking ; the un- 

 der edge, for about half its length from the base, being crenated, and 

 having two short setae springing from one of the crenations or small 

 lobes at about the middle of its length ; the upper edge is serrated. 

 The anterior branch of the rami has four articulations, the first one 

 very short. On the inner edge a rudimentary seta springs from it, and 

 another from the outer edge of the second articulation. One long se- 

 ta springs from the third, and three long setae from the last articula- 



* Syn. Monoculus brachiatus, Jurine. Daphnia brachiaia, Desmarest, Edwards. 

 Desmarest, followed by M. Edwards, quotes the D. macrocopus of Straus as a synon- 

 yme of this species ; but the form of our iusect and that of Jurine's are so different 

 from that given by Straus, in his paper in the ' Mem. du Mus. d'Hist. Nat.' v. t. 29, 

 f. 30, that I hesitate in pronouncing them identical. Jurine's figure is very good, but 

 in the specimens I have examined the head is a little more creel. (See fig. at p. 193). 



