Bibliographical Notices. 59 



well know, been critically cxaiiiined by Mr. C. Darwin, Tlic list, as 

 it now appears, doubled in number and highly valuable for its accu- 

 racy and completeness, has been founded on Mr. Darwin's Mono- 

 graphs, and has been subject to his revision. 



The large number of species accruing from recent researches among 

 the fossil Crustaceans is an important element in this catalogue, and 

 indicates the industry of the observers. The extensive corrections, 

 also, of the generic affinities imply a great amount of labour and a 

 decided advance in our i)alseontological knowledge of this interesting 

 subclass of the Invertcbrata. The Malacostraca, or higher forms, 

 are but few in proportion to the Entomostraca. They aiford only 

 46 species, in 26 genera, and are chiefly Jurassic, cretaceous, and 

 eocene. Their present arrangement and nomenclature are mainly 

 due to Prof. M'Coy. Of the Entomostraca there are three groups 

 which are worthy of notice. Firstly ; the Trilobites so characteristic 

 of the Lower Palseozoic rocks. They are very numerous and present 

 139 species, in 35 genera. The revision of this group has occupied 

 the attention of several foreign and British palseontologists ; we may 

 allude to Barrande *, M'Coy, and Salter. In the preface of the 

 'Catalogue' Mr. Stilter's thorough revision of the list of the British spe- 

 cies is specially acknowledged. The second group referred to consists 

 of 32 species of Phyllopods and Poecilopods, in 1 genera, which are 

 chiefly palseozoic, and known by Salters's and M'Cov's descriptions. 

 Some of the Limnadiadse, however, from recent unpublished obser- 

 vations, appear to range from the Devonian to the present epoch. 

 Thirdly, the microscopic Ostracoda ; of these, 8 1 species, in 9 genera 

 and subgenera, have been arranged in the catalogue by Rupert Jones. 

 At present the majority appears to belong to the Carboniferous, Per- 

 mian, Cretaceous, and Tertiary formations. Those of the first are 

 chiefly Prof. ^M'Coy's species ; the next two groups have been mono- 

 graphed by Mr. R. Jones ; and the tertiary British forms await a 

 similar treatment. In the mean time geologists have M. Bosquet's 

 beautiful treatise on the tertiary Entomostraca of France and Belgium 

 to refer to. The Jurassic strata will probably yield their share in 

 due time. Extensive undescribed collections exist. Altogether, this 

 extensive member of the Entomostracous group promises to afford 

 useful characteristics for the geologist. 



The fragmentary and obscure conditions under which Insect- 

 remains are usually found have rendered it difficult for ]Mr, "West- 

 wood, Mr. Brodie, and their fellow-labourers to specify the exact 

 relations cf the many specimens from the Lias, Great Oolite, Pur- 

 beck, and other formations. The numbers given in the above Table 

 are only approximate ; the specimens themselves are exceedinslv 

 numerous. In the " Addenda," the discovery of Insect-remains in 

 the Wealden by the INIessrs. Binfield is noticed, as well as the re- 

 searches of ]Mr. Brodie and Mr. Westwood in the Purbeck Insects of 

 Dorset. Mr. Westwood's memoir has since appeared, with numerous 

 illustrations. 



* See Annals and Mag. Nat. Hist. 2nd Sir. vol. xii. p. 130. 



