14 BRITISH FOSSIL SPONGES. 



69. 1859 Feomentel, E. de. Introduction a l'Etude des Eponges Fossiles (Mem. 



de la Soc. Linneenne de Norm., T. xi, pp. 1 — 50, Pis. I — IV). 

 The group of Sponges is placed under two main divisions, that of 

 Spongiaires or living Sponges, with a skeleton of spicules, or of spicules and 

 horny fibres ; and that of Spongitaires or fossil Sponges, in which the skeleton 

 consists of a stony meshwork, which may or may not include spicules. The 

 classification proposed is based mainly on the nature of the canal-system, and 

 an altogether subordinate value is placed on the characters of the skeleton. 

 Fossil Sponges are divided into the following suborders, Spongitarla tubulosa, 

 S. osculata, and 8. jporosa. The classification is not a natural one since it 

 includes various forms of siliceous sponges and calcisponges in the same family. 



70. 1859 Thurmann, J., et Btallon, A. Lethasa Bruntrutana, ou Etudes Paleonto- 



logiques et Stratigraphiques sur le Jura Bernois, et en particulier 

 les environs de Porrentruy {Nouv. Mem. de la. Soc. helvet. des Sciences 

 natur.). 

 Numerous species of Sponges, for the most part calcisponges apparently, 

 are described, but only their superficial characters are referred to. 



71. 1860 Feomentel, E. de. Catalogue raisonne des Spongitaires de l'Etage 



Neocomien (Bullet, de la Soc. des Sciences de I'Yonne, 4 e Serie, 



pp. 1—19, Pis. I— IV). 

 Three new genera and several new species are introduced ; the same 

 classification is adopted as in the author's ' Introduction,' and it is stated 

 to be based on positive and natural characters. 



72. 1860 Etallon, A. Sur la Classification des Spongiaires du Haut Jura et leur 



distribution dans les Stages (Actes de la Societe Jurassienne 

 d' Emulation pendant 1858, pp. 129—160, PI. I). 

 Describes very clearly the true character of the skeleton of hexactinellid 

 Sponges as consisting of spicules amalgamated at their points so as to form a 

 regular cubic network. These Sponges are placed in the family of the Dictyo- 

 noccelides. In the family of the Petrospongides the skeleton is supposed to 

 be without spicules, and this family apparently includes calcisponges. A third 

 family is named Clionides. Lithistid Sponges are not particularly noticed, 

 and they are not comprised in the definition of the proposed groups. The 

 author was one of the first to recognise the value of the skeletal structures of 

 fossil Sponges as a basis of classification. 



73. 1860 Capellini und Pagenstecher. Mikroscopische Untersuchungen liber 



den innern Bau einiger f ossilen Schwamme (Zeitsch. f. wiss. Zoologie, 

 Bd. x, p. 364, PL xxx). 

 The spicular structure of several species of hexactinellid Sponges from the 



