Reviews — Desor's and Loriofs Echinologie Ilelvitique. 31 



of the species found in Germany and in tlio adjoining lands, and the 

 spirit his great work elicited was first manifested by the Swiss 

 Naturalists, to whom wo are indebted for the E'chinodermes Fossilea 

 de la Suisse, by Agassiz ; the Catalogue raisonne des E'chinides, of 

 Agassiz and Desor ; the Synojjses des E'chinides Fossiles, of E. Desor ; 

 the Synopsis des E'chinodermes fossiles des Alpes Suisse, of M. Ooster ; 

 and, lastly, the work now under consideration. Other countries, 

 likewise, have contributed their Echinological fauna : thus the fossil 

 E'chinides of France, commenced by the late M. A. d'Orbigny, in 

 the Paleontologie Frangaise, have been ably continued by M. Cotteau ; 

 whilst the British Echinodermata are described in a series of mono- 

 graphs in the volumes of the Palceontographical Society, by Dr. Wright. 

 "Works which, taken together, form an important body of evidence 

 on the history of the extinct sjoecies of one class of the Invertebrata. 

 All these authors admit the great importance of the critical study of 

 the test of the Echinoderm, which constitutes an internal portion 

 of the bodj'^ of the animal, participating in its life, intimately con- 

 nected with the organs of digestion, respiration, and generation, as 

 well as with vision and locomotion, and as a consequence having 

 many of the distinctive characters of the organism indelibly im- 

 pressed on different parts of the skeleton. 



Each great epoch of the world's history has had its own special 

 forms of this class. The Silurian, Devonian, and Carboniferous rocks 

 are rich in wondrously beautiful forms of Crinoidece. The Triassic, 

 Jurassic, and Cretaceous formations are all characterised by numerous 

 extinct generic types of Echinidce ; whilst the Tertiary stages possess 

 groups of the same order that connect the Mesosoic fauna with 

 existing species. The wonderful state of preservation in which 

 many of these fossils are found, renders their study one of much 

 interest, and the teaching derived therefrom, as regards the order of 

 their history in time and space, is of the highest value, seeing that it 

 is based on a very perfect knowledge of their organic characters. At 

 a time when so much is said and written on the Darwinian hypothesis, 

 we invite the special study of Echinoderms to the disciples of this 

 school, as the delicate test of the Urchin has always appeared to us 

 one of the hardest nuts the Darwinian has attempted to crack. In a 

 well written preface, MM. Desor and De Loriol observe : — 



" There is another point of view, which merits in the highest 

 degree the attention of the palaeontologist, because it presents quite a 

 special interest in the group of animals which occupy us : — it is that of 

 the part played by the Echinoderms in the history of the earth, and 

 the verifying of the progress which they have made in the course of 

 ages, and of the modifications which they have undergone from one 

 age to another. In the Echinoderms, as in the Molluscs, the 

 development of families is brought about in a very unequal manner ; 

 and if on one side we see the family of the Cidaridce, continuing 

 almost without variation, and remaining nearly stationary, from the 

 Triassic to the present epoch, we find others, which have developed 

 themselves gradually, enriched with new genera, modified more or 

 less extensively, and often surprising us by the variety and abundance 



