BR0D1E ON FOSSIL INSECTS. 399 



spongy vegetable soil suggest to Mr. Lyell the possibility that 

 we may in this way explain the manner in which vegetable 

 matter has been accumulated to form coal. 



The instances of drift and erratic blocks in North America, 

 quoted by Mr. Lyell, are too numerous to recount. The most 

 remarkable instance perhaps of their occurrence in great abundance 

 is in Long Island, where excavations lately made have exposed the 

 boulder clay to the depth of thirty feet, and in this case the blocks 

 are, some of them, of very large size ; one which is mentioned 

 (although not the largest), measuring 13 feet long, 9 feet broad, 

 and 5 feet thick. Beneath the ordinary boulder clay, there 

 appears to exist a red drift, the detritus of the new red sandstone 

 formation of New Jersey, and this mass is also sometimes of con- 

 siderable thickness. The boulder formation of Long Island 

 contains blocks of very different mineral character in different 

 districts, but the source may in most cases be traced, at least with 

 very considerable probability. 



In the work before us, the geological facts and observations are 

 narrated in the order in which they were noticed and made. 

 We have endeavoured to place before the reader an account of 

 the materials thus brought together, leaving out of view the 

 thread of personal narrative on which the geology is strung, and 

 hoping in this way to add to the usefulness of what we consider 

 to be the great characteristic of the work, the geological map of 

 North America which has been prepared for its illustration. 



D. T. A. 



III. A History of the Fossil Insects in the Secondary rocks of 

 England, accompanied by a particular account of the Strata. 

 in which they occur, and of the circumstances connected with 

 their preservation. By the Rev. Peter Bellinger Brodie, 

 M. A., F. G. S. 8vo. pp. 130. 11 Plates. 



The author of this work has been remarkably successful in the 

 discovery of minute fossils, and is well known to geologists as 

 having worked out points of detail, which by most people would 

 be passed by unregarded. Dwelling for a time in the vale of 

 Wardour, he there discovered in the Wealden beds of the Purbeck 

 series, a curious genus of Isopodous Crustaceans (Archceoniscus), 

 first described from these specimens in the Annates des Sciences 

 by M. Milne Edwards, and also a bed actually loaded with frag- 

 ments of fishes, and the small crustacean of the weald, called 

 Cypris, but containing also the remains of insects. Afterwards, in 

 the vale of Aylesbury, he observed a bed likewise containing re- 

 mains of insects, and occupying the same geological horizon. Re- 

 moving then to Gloucestershire, this indefatigable searcher after the 

 infinitesimal hi Palaeontology very soon succeeded in obtaining from 



