132 History of Britisli Enlomostraca. 



each side a broad longitudinal band, contiguous to the lower margin 

 of the Elytra, formed of a silky plush, which is most probably ser- 

 viceable in retaining the necessary supply of air. The body of Par- 

 nus (Dryops) is entirely covered with this plush, but in Georyssus 

 it is quite naked, and hence M. Wesmael thinks that it is not sub- 

 aquatic, as supposed by M. Audouin, being, indeed, always found 

 upon damp earth. (Annales Soc. Entomol.de France 1835, p. xl.) 

 The genus Elmis and some others constitute a small tribe, which has 

 been appropriately termed Macrodactyle, from the large size of the 

 claws, which enable these insects to retain their stations in the most 

 violent streams. I once found many specimens of several species of 

 Elmis under stones in a mill stream, a yard and a half deep, close 

 to the mill-wheel, where the water must have been constantly in 

 agitation. The entire structure of these insects, and especially of 

 the mouth, exhibits a striking contrast with that of Aepus, &c , origi- 

 nating in the difference of their habits and motions, the Elmidas 

 feeding upon minute aquatic vegetable matter, and their movements 

 being exceedingly slow. 



The habits of the Enicoceri, as detailed in Mr Wailes' interesting 

 paper in the Entomological Magazine, No. 3, are somewhat diffe- 

 rent from those of Elmis ; but as I have not recent specimens of 

 those insects, I am unable to institute an examination of the cloth- 

 ing of the body, &c. which would doubtless satisfactorily elucidate 

 the cause of such difference. 



IV — The Natural History of the British Enlomostraca. By Wil- 

 liam Baird, Surgeon, H. C. S. Plate V. (Continued from Vol. i. 

 p. 526.) 

 Sp. III. — Cypris strigata. " Testa reniformi, fusca, fasciis tri- 



bus albis." 

 Habitat.— Tool on sea shore, a little above high water-mark, at Thornton 

 Loch, East Lothian. 



Synonimes ^Cypris strigata, Muller, Zool. Dan. prodrom. p. 199, No. 2387. 1776. 



Cypris strigata, Muller, Entomostraca, p. 54, tab. iv. fig. 4-6. 1785. 



Monoc. strigatus, Gmelin, Lin. Syst Nat. 3002, No. 37. 1788. 



M. strigatus, Manuel, Encyc. Method. Hist. Nat. Tom. vii. p. 726, No. 31. 1792. 



M. strigatus, Fabricius, Entomol. system, Tom. ii. p. 496. 1793. 



Cypris strigata, Latreille, Hist. Nat. gen. etpart. des Crust. &c. Tom. iv-p. 245. 

 1802. 



Cypiis strigata, Ramdohr, Beyt. zur Naturg. einig. deut Monoe. arten, pp. 14- 

 17, tab.iv. fig. 1-14. 1805. 



Mon. strigatus, Rees' Cyclopaedia, Art. Monoculus. 1819. 



Mon. bistrigatus ? Jurine, Hist, des Monoc. p. 177, pi. 19, fig. 12-13. 1821. 



Cypris strigata^ Desmarest, Cons. Gen. sur les Crust, p. 386. 1825. 



4 



