ZOOLOaY AND BOTANY, MICKOSCOPY, ETC. 471 



certain age, make their way into the endoderm ; in E. ramosum they 

 are developed in the endoderm. The author considers that if two 

 species of the same genus act thus differently the origin of the 

 generative products from one or other germinal layer is not a matter 

 of prime importance. It may, however, be suggested that a difference 

 of this kind is of importance enough to justify the generic separation 

 of the two species in question, and it does most certainly bring to the 

 front again the vexed question as to the real value of the characters 

 on which genera and species are so frequently established. 



Porifera. 



New Lyssakine Hexactinellid.* — Professor SoUas describes a 

 new fossil Hexactinellid sponge from the Niagara chert beds of 

 Hamilton, Ontario. It is the second oldest known example of the 

 Lyssakina. The author proposes for it the name of Astroconia Granti, 

 the former in allusion to the peculiarly spinose character of the rays 

 of the sexradiate spicules. The anchoring spicules consist of a 

 straight shaft with four recurved rays, each having a small bifid spine 

 near the base on the outer surface. It is the next oldest sponge to 

 Protospongia. 



Fossil Sponge Spicules.f — The chalk-pit at Horstead, Norfolk, 

 contains many large variously- shaped nodules of flints, strewn about 

 after the removal of the soft chalk in which they had been imbedded. 

 One of these, about a foot in diameter, and more spheroidal than the 

 generality of the potstones, attracted the attention of Dr. G. J. Hinde. 

 It exhibited a central cavity, which contained a quantity of material 

 resembling fine flour in appearance and feel, and of a creamy white 

 tint. The material, when prepared for examination, weighed about 

 three or four ounces. 



The author describes, from it, 160 forms of spicules, which he 

 refers to thirty-eight species and thirty-two genera of sponges, 

 fourteen of the species belonging to the Lithistids and Hexactinellids. 

 Besides the spicules of sponges, there were in the cavity remains of 

 Foraminifera, Ostracoda, Echinodermata, Annelida, Cirripedia, Poly- 

 zoa, Brachiopoda, Lamellibranchiata, and Fishes, the first two kinds, 

 with the sponges, being far the most abundant. The abundance of 

 the sponge spicules sustains the author's conclusion that flint nodules 

 of the chalk have resulted from the aggregation of the siliceous 

 spicules or skeletons of the sea-bottom sponges, as the chalk from an 

 aggregation of the shells of Foraminifera, Ostracoda, and other cal- 

 careous secretions of the same seas. 



Protozoa. 

 BiitscMi's 'Protozoa.' — The sixth and seventh parts of this pub- 

 lication have been issued ; they consist chiefly of the " system " of 

 the Ehizopoda, but have also some remarks on the habits of life, mode 



* Abstr. Proc. Geol. Soc, 1881, pp. 50-1. 



t Hinde, G. J., 'Fossil Sponge Spicules from the Upper Clialk, found in the 

 interior of a single flint-stone from Horstead in Norfolk,' 83 im. (5 pis ) rsvo 

 Munich, 1880.) if k f -j- k • 



