promises to be of great value, as regards the classification and dis- 

 tribution of the species, and in which the quinarian system is adopted. 

 The first part of a treatise upon this class by Milne Edwards ' lias 

 lately appeared in Paris, which will form a standard \\ ork of re- 

 ference when completed. The indefatigable Dr. Johnston of Berwick- 

 upon-Tweed has from time to time published isolated descriptions of 

 rare or unknown animals belonging to this class in the late numbers 

 of the Magazine of Natural History ; whilst a valuable memoir upon 

 the natural history of that destructive animal the Limnoria terebrans, 

 from the pen of Mr. Coldstream, appeared in 'Jameson's Edinburgh 

 Philosophical Journal' of last year. But the subject of the highest 

 interest connected with this class, is that of the transformations which 

 these animals have universally been asserted to undergo in their early 

 age, contrarj' to the generally received opinion that the Malacostraca 

 are not subject to metamorphoses. The singular facts relative to this 

 subject published by Mr. J. V. Thompson of Cork-, (amongst which 

 the most remarkable is the statement that some of the animals com- 

 posing the extraordinary genus Zom are in fact only the young of 

 the common edible Crab,) are sufiicient, if the correctness of them 

 shall be established, to place this author in the foremost ranks of 

 science ; but it is to be observed, that the elaborate researches of 

 Rathke upon the development of the eggs of the Cray-fish ' and of the 

 common Asellifs aguaticus*, the observations of M. Milne Edwards 

 in the work above alluded to as well as in several of his detached 

 memoirs, and those of Mr. J. E. Gray lately read before the Royal 

 Society, relative to the transformations of the Cirripedes, tend to throw 

 some doubt upon the statements of Mr. Thompson. The subject was 

 considered worthy of a place amongst the zoological queries by the 

 British Association at Cambridge ; and the Zoological Society of 

 Dublin have likewise adopted the same inquiry as one of the sub- 

 jects for the prize essays which they have proposed. It is to be ob- 

 served, however, that the correctness of Mr. Thompson's observations 

 upon the transformations of the Cirripedes has found a supporter in 

 Dr. Burmeister ^, who is thus opposed to Mr. J. E. Gray, and that Dr. 

 Nordmann has ascertained the transformations in that remarkable 

 group of animals the Lern(Z<K^. Mr. Thompson has likewise sub- 



' Histoirc Naturelle des Cnistaces, comprenant I'Anatomie, la Physiologie et la 

 Classification de ces Animaux. Par M. Milne Edwards. Vol. I. Paris, 1834. 8vo. 

 With an atlas of plates, forming portion of the Suites a RufFon. 



- Zoological Researches and Illustrations on Natural History of Nondescript or im- 

 perfectly known Animals, in a Series of Memoirs, illustrated by numerous Figures. 

 By J. V. Thompson, Esq., F.L.S. 8vo, Nos. 1—5. Cork, 1828—1834. 



3 Untersuchungen iiber die Bildung and Entwickelung der Flusskrebses. Folio. 

 Leipzig, 1829. With plates. 



^ Abhandlungen zur Bildungs ant Entwickelung Geschichte der Mcnschen und 

 der Thiere. 4to, Leipzig. 18;>2 — 1833. With plates. 



' Beitrage zur Naturgeschichte der Ramkenfusser (Cirripeda). Von H. Bur- 

 meister. Berlin, 1834. 



® Mikrographische Beitrage zur Naturgeschichte der Wirbellosen Thiere. Von 

 Dr. Alex. v. Nordmann. Berlin, 1832. 4to. With plates. 



Dr. Burmeister of Berlin has likewise published a valuable Memoir upon the 



