HISTORY OF GEOLOGY AND PALEONTOLOGY. 



A short treatise on the classification of the Echinidea, written 

 by Albert Gras in 1848, was in so far important as it formed 

 the basis of the Synopsis of fossil Echinids drawn up by Desor, 

 which has been a standard authority for many decades. 

 In 1848 also, the first researches of Cotteau and Forbes 

 on fossil Echinids were published, and these were rapidly 

 succeeded by D'Orbigny's account of the irregular Echinids of 

 the French Cretaceous formation and Wright's beautifully illus- 

 trated monographs of the Jurassic and Cretaceous Echinidea 

 in Britain. After the deaths of Forbes, D'Orbigny, and 

 Wright, Cotteau 1 was for a whole decade almost the only 

 contributor to this field of research. In his Paleontologie 

 Francaise, and in numerous other works and special memoirs, 

 Cotteau advanced the knowledge of the fossil Echinidea in a 

 degree unrivalled by any other observer before or since. All 

 his writings are distinguished by extreme accuracy and acute- 

 ness of observation. As regards the systematic questions, 

 Cotteau adopts in great measure the classificatory groundwork 

 supplied by Desor and Wright. A large number of palaeonto- 

 logists have taken up the study of Echinidea in recent years, 

 and the majority follow the lines of Desor's Synopsis and 

 Cotteau's results. 



The observations on remains of fossil Holothuridea are 

 comparatively few. They are confined to the description of 

 isolated parts of the dermal skeleton, such as the wheel-like 

 spiculae of certain species of Chirodota described by Moore 

 from the British Jurassic deposits, and several fragments of a 

 similar character, which have been described by Von Siebold, 

 Schwager, Etheridge, and others, occurring in strata of various 

 geological ages. 



Worms. The soft perishable character of the bodies of worms 

 renders them unsuitable for the slow processes cf petrefaction, 

 and we find in consequence that palaeontological literature 

 contains few references to these organisms, and can bring 



1 Gustave Cotteau, born I7th December 1818 in Auxerre, studied law at 

 Auxerre and Paris, and began his career in 1846 as judge in his native 

 town, in 1857 was transferred to Bar-sur-Aube, in 1858 to Coulommiers, 

 and in 1862 returned to Auxerre as a Member of the Tribunal. Cotteau 

 was regarded as the first authority in the domain of fossil Echinidea; the 

 French Institute in 1887 elected him a Corresponding Member, the Geo- 

 logical Society of France twice elected him President. He died on the 

 loth August 1894, at Auxerre. 



