634 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
of calcite, and, witliin a considerable range, would appear neither to 
influence nor be influenced by selective mortality in the species among 
which it occurs.” The position is elaborated in considerable detail. 
In the second part of the paper the author criticises the classifica- 
tion of sponges according as they are homocoel or heterocoel, and, 
without prejudging the question as to whether there is or is not a natural 
class Calcarea, he proposes to establish two sub-classes — (1) Calcaronea, 
and (2) Calinea. These sub-classes arc mainly based on the two points 
already noticed by Minchin, that in the first division the nucleus of 
the collar-cells and of the flagellate cells of the larva is distal, and the 
flagellum arises from it directly, while in the second the flagellum does 
not arise directly from the nucleus, which is basal ; and that in the first 
case the larva is an amphiblastula, in the second a parenchymula. 
The two sub-classes are also characterised by their spicules, the first to 
appear in the one case being oxea, and in the second triradiates. Detailed 
diagnoses are given of the sub-classes and their orders, and in some cases 
also of the families. 
Calcareous Sponges from the White Sea.* — Herr L. L. Breitfuss 
describes a collection from the White Sea and from the Murman or 
Barent Sea. Altogether there are 41 Arctic species on record, — 
15 Asconidm, 20 Syconidae, and 6 Leuconiidae, and there seems to bo 
great uniformity in the circumpolar distribution. 
Protozoa. 
Deep-water Deposits from the Red Sea.f — Dr. E. Graffe describes 
the composition of the ooze from depths of 1000 m. or more in the 
Red Sea. It may be described as midway between Globigerina- and 
Pteropod-ooze. The list includes a large number of Foraminifera, 
2 Radiolarians, 13 Pteropods, and 2 Heteropods. 
Classification of Ciliata.j; — Dr. Y. Sterki maintains that the Peri- 
tricha are quite distinct from all the other Ciliata, which he terms 
Pantotricha. He subdivides the Pantotricha into Gymnostomata and 
Trichostomata (em.), and recognises three orders of Trichostomata, viz. 
Aspirotricha, Oiigotricha (em.), and Zonotricha. 
Licnophora.§ — Sig. A. Garbini gives a short description of Licnophorci 
europsea sp. n. from fresh water at Verona. A similar form ( L . setifera ) 
was described from fresh water in New Zealand by Maskell (1886), but 
Biitschli doubted its validity, which Garbini now confirms. His dis- 
covery is a remarkable Protozoon, very contractile, and Protean in form. 
The posterior region is irregularly rectangular, and bears two groups of 
minute setae ; the anterior region forms a right angle to the posterior 
part, and is covered with short cilia. The terminal oral aperture is 
surrounded by numerous long cilia. 
Luminosity of Ceratium tripos. || — Herr J. Reinke states that the 
luminosity of this marine organism may be incited by a variety of 
* Mem. Acad. Imp. St. Petersbg., vi. (1808) p. 41 (4 pis.). 
t SB. K. Akad. Wiss. Wien, cvi. (1897) pp. 431-8. 
1 Amer. Natural., xxxii. (1898) pp. 425-8. 
§ Zool. Anzeig., xxi. (1898) pp. 513-4 (2 figs.). 
|| Wiss. Meeresunters. v. d. Comm. z. Unters-. d. deutschen TMeere in Ki 1, N.F., 
iii. p. 39. See Bot. Ztg., lvi. (1898) 2 te Abtli., p. 282. 
