ENTOMOSTRACA. 



Goodsir (Edinb. New Philosoph. Jouru. xxxv, p. 102) lias investigated 

 in the Firth of Forth what the fishermen there term " Maidre." It is con- 

 stituted of vast and connected masses of living animals, among which 

 Amphipoda, Cirripedia, and Acalephse occur abundantly, but is principally 

 composed of Eutomostraca. These waters are invaded not only by immense 

 shoals of " Coal-fish," and small ones of Herrings, but also by various 

 Cetaceans, particularly Dolphins, and Porpoises, and even the Rorqual is occa- 

 sionally seen. The author thinks that these Cetaceans are not in pursuit of 

 the fish in order to feed upon them, but that they participate with them in 

 the food afforded by the " Maidre," as he has never observed a fish in the sto- 

 mach of a Dolphin or Porpoise. He also found, on a visit in May to the 

 so termed island, the water over a large circuit coloured red, owing to the 

 presence of an Entomostracou, which proved to be Cetochilits. Thus the 

 multitudinous occurrence of the almost invisible Eutomostraca is the con- 

 dition of existence of the vast shoals of fish as well as of the gigantic marine 

 Mammalia. 



CLADOCERA. Baird (Ann. Nat. Hist, xi, p. 81), in the continuation of 

 his 'Natural History of the British Entomostraca,' the progress of which has 

 been interrupted for several years, has subjected the genus Lynceus, Mull., 

 to a thorough investigation. The generic characters, which have been erro- 

 neously understood by all writers, chiefly require emendation, and the author 

 thus constitutes them : Rami two, usually very short, branched, each branch 

 three-jointed. A single eye ; in front of which is a black spot ; five pairs of 

 feet ; intestine convoluted, tail jointed. The author divides the British 

 species into eight subgeuera. (1) Subgeuus, Nacrothrix: anterior branch of 

 the ramus, with a very long seta at the root of the second joint ; antenna 

 pendulous, from the extremity of the beak : M. laticornis (Monoc. lat., Jur.) 

 (2) THurycercus : sub-quadrangular, tail very broad, in form of a flat plate, 

 densely serrated : E. lamellatus (L. lam., Mull.) (3) Chydorm, Leach : almost 

 spherical, beak very long and sharp, curved nearly into a crescent; 

 rami very short : Ch. spheericus (L. sph., Mull.) ; and a new species, Ch. glo- 

 bosus. (4) Camptocercm : ovoid, tail long, slender, very flexible, serrated : 

 C. macrourus (L.macr., Mull.). (5) Acroperus: somewhat harp-shaped, ter- 

 minating inferiorly on anterior margin in a more or less blunt point projecting 

 forwards ; rami rather long : A. harpa (L. harpa, Baird) ; and a new species, 

 A. nanus. (6) Alona : shell quadrangular, striated, rami short : A. quadran- 



