ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 1011 



The most striking feature of the adult is the great bulk of the lobes, 

 which are thicker than the body and nearly circular. 



Beroid of Port Jackson.* — Dr. E. v. Lendenfeld redescribes 

 Neis cordigera Lesson, first described in 1824 by the naturalists of 

 the ' Coquille,' and not since found. 



He considers that Neis represents a genus quite distinct from 

 Berce. Its sexual cells are matured in the vascular reticulation 

 exclusively, to which place the ova migrate from the meridional 

 canals. The style-cells, described as sensitive elements by K. 

 Hertwig and Chun, he considers to be " poison-thorns," and the 

 glands surrounding these cells to be poison-glands. 



Australian Hydromedusge.j — Dr. E. v. Lendenfeld describes and 

 figures eight new species and a few previously insufiiciently known 

 ones, the paper forming an addendum to the monograph of Australian 

 Hydromedusfe previously published. It brings the total number of 

 Australian species up to 240, distributed amongst seventy-four genera. 

 A second addendum | contains some alterations in the author's classi- 

 fication. 



Porifera. 



Histology and Nervous System of Calcareous Sponges.§— Dr. 

 E. von Lendenfeld describes the three layers of calcareous sponges. 

 The mesoderm is stated to consist of " gallert of a pretty high degree 

 of density," and is never fibrillar, as in some other sponges ; it contains 

 stellate or rarely bipolar cells, which perhaps represent the muscular 

 element. The structures of the spicules are best studied after treatment 

 with " chloride of gold-potassium " for twelve hours, which reveals 

 the presence of small parallel radially-arranged prisms. Spiral 

 muscle-cells form contractile sphincters by which the pores can be 

 more or less closed. Amoeboid cells are to be found in all Calcarea ; 

 the ova are transformed amceboid cells, which, when mature, are 

 inclosed by endothelium ; the first stages of development are passed 

 through in the body of the parent. The gland-cells are either single, 

 or arranged in small branches ; highly refractive granules are to be 

 found in their interior. Si^indle-shaped mesodermal cells, which 

 protrude beyond the outer coating of ectoderm, are to be found in the 

 Heteroccela, and arc regarded as sensory. Multipolar gauglion-cells 

 have been observed in several species. 



Reproduction of Spongilla lacustris.|| — Dr. W. Marshall com- 

 municates a preliminary note as to the reproductive processes in this 

 fresh- water sponge. 



(a) Formatiun of gemmulae. — The gemmulae or winter embryos are 

 formed in the neuter autumn Spongillae from wandering nutritive 

 amceboid cells (" trophophores ") which accumulate in the inhalent 

 canals or in the ciliated chambers, whence they pass into mesoderm, 



• Proc. Linn. Soc. N. S. Wales, ix. (1885) pp. 9G8-76. 



t Il.if]., pp. 908-24 (4 plH.). I Ibid., pp. 984-5. 



§ Ibid., pp. 977-83. || SB. Naturf. Gesell. Leipzig, 1884, pp. 22-9. 



