24 Reviews — Reliqum Aquitamcce. 



testifies to the immensity of time required for the deposition of this older Palaeozoic 

 group of rocks, and the life history of the species in this large and highly organised 

 group, which added to that of the Gasteropoda, forcibly suggests a still more remote 

 and lost fauna, from which these descended, reaching far back to Laurentian, and 

 pre- Silurian ages. The genus Natitihis now represented by one species^ (in the 

 Silurian seas by 2 1 ) is the only form that has survived through the stream of time, 

 and each succeeding life-period has seen their decrease in number. Space only 

 forbids us entering into further analysis of this important class of moUusca. 



That numerous errors during the progi^ess of the compilation of the Thesaurus 

 should creep in, and occur, is to be expected, and under certain groups many occtir; 

 these are chiefly in the synonomy of the GraptolitidcB (Hydrozoa) — some 30 species 

 are thus duplicated, arising from the author's misconception of the species placed 

 under several genera by different writers upon this group — especially Hall, Geinitz, 

 and others — scattered through many memoirs. A proper analysis of the large genus 

 Graptolith2is as used by Hall, with those adopted by every other author, would 

 have prevented this. Again, many genera of the Phyllopoda, Ostracoda, and 

 Branchiopoda, as now recognized, should have received more careful analysis relative 

 to their synonomy, etc. ; the same species occurring, as in the Polyzoa, under 

 different genera.- These errors give a plus or minus value to the species, and 

 also to the groups, and, where tabulated, are perpetuated in the same ratio, and 

 right or true deductions upon migration, recurrence, locality, and the longevity and 

 extinction of species can only be drawn from correct identification ; these errors in the 

 table, however, are readily corrected by those possessing sufficient knowledge, and 

 need not be perpetuated in succeeding analyses, and the author himself may (if 

 not in another edition) do so in some other form. 



We trust that every scientific library, either private or public, will make a point 

 to possess a copy of this great muster-roll of eveiy species known m the Silurian 

 rocks of the globe. 



R. E. 



II. — Eeliqui^ Aquitanic^ ; Being Contributions to tlie Archseology 

 and Palaeontology of Perigord and the adjoining Provinces of 

 Southern France. By Edouard Laetet and Henry Christy. 

 Edited by Prof. T. Eupert Jones, F.G.S. Parts VL and VII. 

 August and September, 1868. 



OUE last Notice of this work appeared in the Geological Maga- 

 zine for June, 1868, Volume V., p. 282. Part VI. concludes the 

 observations and comparisons between the implements, etc., from the 

 Caves of Perigord, and the implements used among the Laps and 

 North American Indians. On this subject the letter of Mr. Eobert 

 Brown (who has only lately returned from a protracted residence in 

 "Western North America) will be read with great interest. 



This is followed by " An Account of the Human Bones found in 

 the Cave of Cro-Magnon in Dordogne, by Dr. Pruner-Bey," illus- 

 trated by six chromo -lithographic plates. Five of the plates are 

 devoted to the crania, and one to limb-bones. The description of 

 these remains extends into Part VII. At p. 71, Dr. Pruner-Bey 

 writes : — " The presence at all levels of the same kind of flint- 

 scrapers, as finely chipped as those of the Gorge d'Enfer, and of the 

 same animals as in that classic station, evidently shows them to be 

 relics of the successive habitation of the Cro-Magnon shelter by the 



1 Nautiltis poinpilius, the only Tetrabrajichiate Cephalo;pod living ; in the Silurian deposits 

 there are 1420 known species. 



a The same may be said with reference to many names given in the addenda, some of which 

 it \vill be seen are repeated in the general text. 



