14 BRITISH FOSSIL SPONGES. 
69. 1859 Fromenten, EH. pe. Introduction a l’Htude des Eponges Fossiles (Mém. 
de la Soc. Linnéenne de Norm., T. xi, pp. 1—50, Pls. 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, Spongitaria tubulosa, 
S. osculata, and S. porosa. The classification is not a natural one since it 
includes various forms of siliceous sponges and calcisponges in the same family. 
70. 1859 Tuurmann, J., et Hratton, A. Lethzea Bruntrutana, ou Ktudes Paléonto- 
logiques et Stratigraphiques sur le Jura Bernois, et en particulier 
les environs de Porrentruy (Nouv. Mém. 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 Fromenret, E. pr. Catalogue raisonné des Spongitaires de l’Etage 
Néocomien (Bullet. de la Soc. des Sciences de lYonne, 4° Série, 
pp. 1—19, Pls. 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. 
NJ 
bo 
1860 Hratton, A. Sur la Classification des Spongiaires du Haut Jura et leur 
distribution dans les Etages (Actes de la Société Jurassienne 
@ Emulation pendant 1858, pp. 1Z9—160, Pl. 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- 
noceelides. 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 Capntiint und Pacrnstecuer. Mikroscopische Untersuchungen iiber 
den innern Bau einiger fossilen Schwiimme (Zettsch. f. wiss. Zoologie, 
Bd. x, p. 364, Pl. xxx). 
The spicular structure of several species of hexactinellid Sponges from the 
