40 
bo 
4 
ior 
bo 
— 
NI 
219. 
BRITISH FOSSIL SPONGES. 
respecting the skeleton of Astylospongia, and now regards it as consisting of 
simple rodlike spicules branching at both ends. By the interlocking of the 
branching extremities the nodes are formed. The family Astylospongide is 
removed from the Hexactinellide and placed with the Anomocladine family of 
lithistids. The previous definition of the characters of this family is altered, 
and the elementary spicules of the skeleton are stated to consist of simple, 
straight or curved, rod-like spicules with branching extremities. In the family 
are included Astylospongia, Paleomanon, Protachilleum, Hospongia, Melonella, 
Cylindrophyma, Mastosia, and the existing genus Vetulina. The genus 
Didymosphera, Link, is regarded as equivalent to Cylindrophyma, Zitt. 
Lecanella, Zitt., and Hindia, Dune. are placed in the family Megamorina. 
5. 1884 Poovra, P. Ueber isolirte Kieselspongiennadeln, aus der bohm. Kreide- 
formation. Ueber Spongiennadeln des Briisauer Hornsteines 
(Sitzungsber. der. k. bohm. Gesell. der Wiss., pp. 1—14, 243—254, 
3 pls). 
Numerous detached spicules of tetractinellid, lithistid, and also of 
hexactinellid Sponges are described and figured. Many are similar to those 
occurring in the Cretaceous strata of England. 
. 1884 Hinpz, G. J. On the Structure and Affinities of the Family of the 
Receptaculitidz, including therein the genera Ischadites, Murch. 
(= Tetragonis, Hichw.); Spherospongia, Pengelly ; Acanthochonia, 
gen. noy., and Receptaculites, Defrance (Quart. Journ. Geol. Soc., vol. 
xl, pp. 795—849, Pls. XXXVI—XXXVII). 
These fossils are regarded as siliceous hexactinellid Sponges in which one 
ray of the regular spicule is modified to form a rhomboidal or hexagonal 
plate. The history and geological distribution of the genera are given, as well 
as a revision of the different species. 
. 1884 Hinpr,G. J. On Fossil Calcisponges from the Well-boring at Richmond 
(Quart. Journ. Geol. Soc., vol. xl, pp. 778—783, Pl. XXXY). 
Describes several new species of minute Sponges, in some of which the 
spicular structure can be distinguished in thin sections. The strata from whence 
they come are probably of Jurassic age. 
1884 Hatt, James. Descriptions of the Species of Fossil Reticulate Sponges, 
constituting the Family Dictyospongidee (Thirty-fifth Annual Report 
of the New York State Museum, pp. 465—481, Pls. 18—21). 
These bodies are described as fronds consisting of a reticulation of tubular 
spicules forming rectangular meshes, which alternate in size and strength, 
owing to the alternation in the size of the bundles of spicules. Three layers 
are stated to be present. Nothing is stated of the form of the spicules, The 
