1869.] GEOLOGY AND MINERALOGY. 345 



fish that had lived by eating their fellows, * and of the dead 

 whale that had strained from the water myriads of their con- 

 geners for his daily food. When the sailors, in one of I'arry's 

 voyages, hung their salt beef over the ship's side in the water 

 for a while, it soon disappeared under the combined attack of 

 these little devourers; and if a fish be put in a perforated 

 canister in a suitable stream or pond for a couple of dajs, its 

 skeleton will be prepared by the tiny Crustaceans. Just as Mr. 

 Charles Moore has found in the Lias of Somersetshire, the fossil 

 reptiles overlain by a swarm of Ammonites, buried with the 

 half-eaten carcase in the mud, so the fossil remains of the fishes 

 (as noticed by Phillips, Binfield, myself, and others) are often 

 and often found imbedded with innumerable carapace-valves of 

 the Entomostracous scavengers in mud-beds of all ages, especially 

 the Carboniferous, Wealden, and Tertiary clays); nor are 

 Entomostraca wanting among the bones of fish and reptile in the 

 Lias above alluded to. 



Thus also we have seen a crowd of Cyprides and Candonce 

 cleaning out the shell of a Paludina or a Limnceus in an 

 aquarium; and in the fossil state we know that valves of 

 Entomostraca are sometimes associated in the shells of Mol- 

 luscs, Thus Mr. J. W. Kirkby says ('Trans. Tyneside Nat. 

 Field-Club,' vol. iv. 1859,) " The convex valve of a Conchifer 

 appears to have been a popular place of resort with the Bairdice, 

 for out of one I procured some dozens of individuals." 



The rapid increase of some kinds of Entomostraca, and the 

 tenacity of life possessed by the eggs, are circumstances that 

 have attracted the attention of naturalists. The almost sudden 

 appearance of Apus and of Estheria in great numbers in ditches, 

 and even in cart-ruts, after, heavy summer rains, in Ger- 

 many and France, has been particularly noted. Here allusion 

 need be made to these facts only to remind the reader that the 

 dried mud of ponds will nearly always be found to contain the 

 still vital eggs of various species of Entomostraca ; and if small 

 portions be sent home from abroad, and placed in pure water, the 

 species belonging to the original pond may be produced under 

 the eye of the naturalist and properly recorded. Thus, Mr. 

 Henry Denny and Dr. Baird had the pleasure of raising in 

 England, from dried mud sent by Dr. Atkinson from Jerusalem, 



* See Dr. Baird's " Notes on the Pood of some Fresh-water Fishes 

 more paiticularly the Vandace and Trout." 1857. 

 YOL. IV. X No. 3. 



