180 Reviews — The Palteontographical Society's Monographs. 



the general reader, but it comprises a valuable store of facts, 

 supplemented in an Appendix with the record of a number of well- 

 sections and borings; and these will be of both practical and 

 scientific value to many living in the district, while they must also 

 aid the theorist in his efforts to account for the formation of the 

 deposits, more especially those belonging to the Glacial period. It 

 will be remembered that in his Memoir on the Geology of the 

 Eenland, Mr. Skertchly spoke with some confidence as to the 

 classification of the Glacial deposits, and of the land-origin of the 

 Chalky Boulder-clay. But we are not treated here to theoretical 

 views. Mr. Penning tells us in regard to the Boulder-clay that it 

 was evidently formed in one continuous sheet, that it rarely presents 

 any signs of stratification, and that its main substance consists of 

 material derived from the rocks at no great distance from the point 

 where it may be observed — facts which coincide with those observed 

 by Mr. Skertchly, and upon which, in part, he based his conclusions. 



II. Monographs published by the Pal^ontographical Society. 



4to. vols. xxxi. and xxxii. 1877-8. 



IN 1877 Mr. S. V. Wood supplemented the Monograph of the 

 Eocene Bivalve Molluscs, written by the late Mr. E. E. 

 Edwards and himself, with valuable figures and descriptions, chiefly 

 of Cyrena and Cyclades, so important in the history of the Woolwich 

 and Reading beds. He also * added an instalment, unfortunately 

 the last that he feels able to contribute, to the Monograph of the 

 Eocene Gasteropoda, commenced by the late Mr. Edwards, and 

 continued by himself. Species of the genera Helix, Cyclostoma, 

 Bulimus, Succinea, Bythinia, Planorbis, Limncea, Neritina, and Nerita, 

 are the chief subjects of this memoir and its plate, which last has 

 been well and characteristically drawn by Mr. G. B. Sowerby. 



Dr. Lycett continued his exhaustive Monograph on the Trigonice 

 in 1 877. Many of the Costatce, and one of the Byssifercs, together 

 with several supplemental species, only lately come to hand, are 

 described and beautifully figured in this part iv. Two specimens 

 from Australia and Lebanon are given in woodcuts for comparison. 

 The lithograph plates, by Lichtenbauer, are beautifully drawn, but 

 give an unnaturally clean and smooth surface to the fossils. 



Dr. Traquair's Monograph of the Carboniferous Eishes begins 

 with the PalceoniscidcB for part i. (1877). It has an instructive 

 Introduction, both geological and zoological ; and treats of Cosmo- 

 ptychius striatus (Ag.) ; ElonicJitliys semistriatus, Traq.; E. caudalis, 

 Traq. ; E. oblongus, Traq., and E. striolatus (Ag.) ; with seven most 

 teaching and illustrative plates, lithographed from drawings made 

 by Dr. and Mrs. Traquair. 



Professor Owen in 1877 enriched palasontology with a concise 

 and masterly account of a great carpal spur or spine of the gigantic 

 Omosaurus hastiger, from the Kimmeridge Clay, illustrated with 

 large drawings ; and in 1878 he continued his Monograph on the 

 Wealden and Purbeck Reptiles, with descriptions and numerous 



