ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
633 
Ccelentera. 
Arctic Hydromedusse.* — Gbsta Gronberg gives a list of 41 species 
which have been found in the Arctic region, and describes two new forms, 
Sarsia brachygaster sp. n., and Solmundus glacialis sp. n., besides others 
already more or less satisfactorily diagnosed. 
New Actinarian.f — Mr. E. L. Mark describes a very remarkable 
new form found during the c Albatross ’ expedition, which he regards as 
a sea-anemone possibly allied to Ceriantlius , and calls Branchiocerianthus 
urceolus. The disc is oval and much higher at one end than at the 
other, the marginal tentacles 85-97 in number, and arranged in the 
form of a horseshoe. The oral tube rises above the level of the disc, 
and is surrounded by numerous (about 130) oral tentacles. Between 
this tube and the marginal tentacles are a varying number (21-37) of 
paired branched organs, called by the author £< gills.” The column 
resembles that of Ceriantlius , and its lower bulb-shaped termination is 
invested by a complex sheath. The description is preliminary only. 
Alcyonaria from Spitzbergen.J — Herr Walther May describes the 
Alcyonaria found by Kiikenthal and Walther off the east coast of Spitz- 
bergen. They all fall into Kiikenthal’s genus Paraspongodes , which 
includes most of the new genera founded by Danielssen. The genus is 
defined by the following characters : — Nephthyidae without supporting 
fasciculi, the polypes single or united in clusters. The specimens 
include six species, of which two are new. Full details as to distri- 
bution are given, an interesting point being that the species are cold- 
water animals, and the depth at which they live is determined apparently 
by temperature only. Thus Paraspongodes fruticosa occurs on the west 
coast at a depth of 600 fathoms, but on the east in 52 fathoms, this 
being apparently due to warm and cold currents respectively. 
Structure of Xenia.§ — Mr. J. H. Ashworth has a note on certain 
points in the anatomy of a species of the Alcyonarian Xenia. In this 
species the six short mesenteric filaments of most Alcyonarians are 
absent, but the stomodaeum contains secreting “ goblet-cells,” which pro- 
bably perform the digestive function usually discharged by the cells of 
the filaments. Certain of the endoderm-cells are remarkable in that 
they are each furnished with a long pseudopodium, which may be from 
four to eight times the length of the cell. 
Porifera. 
Calcareous Sponges. || — Mr. G. P. Bidder discusses certaint points 
connected with the skeleton and classification of these sponges. He 
believes that in the formation of spicules too little stress has been laid 
upon tension as an important factor, and differs from Minchin in be- 
lieving that the explanation of the exact geometrical figure of any spicule 
is to be sought in crystallography rather than in physiology. “ The 
angles of a triradiate calcareous spicule are dictated by the properties 
* Zool. Jahrb. (Abth. Syst.), xi. (1898) pp. 451-68 (l pi.). 
t Bull. Mus. Comp. Zool., xxxii. (1898) pp. 147-54 (3 pis.). 
X Zool. Jahrb. (Abth. Syst.), xi. (1898) pp. 385-404 (1 pi.). 
§ Proc. Roy. Soc. Lond., lxiii. (1898) pp. 443-6 (3 figs.). 
|| Op. cit., lxiy. (1898) pp. 61-76 (10 figs.). 
