352 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
pose to call P. Jonesi. They point out that its interest is due to the many 
primitive characters united in it. It seems not unlikely that the higher 
calyculate Campanularian Hydroids have descended from athecate 
ancestors, more or less like Perigonimus ; though a “ naked hydroid,” it 
has a covering, and that such a one as an animal like a hydroid might 
have in the earlier stages of the acquisition of a strong skeleton. It is 
not a highly differentiated product, but a delicate slightly compacted 
slime, though very unlike the mucous secretions that all animals are so 
commonly throwing off from their bodies. If a semi-fluid coat of this 
sort were stiffened only a little, we should, the authors say, arrive at 
the more compact chitinous cuticle of the calyculate forms. It is urged 
that the differences between the gelatinous and the chitinous cuticle are 
such differences in the chemical or metabolic functions of cells as could 
conceivably come within the range of the operation of natural selection. 
Porifera. 
Hexactinellid Spicules.* — Prof. F. E. Schulze discusses the deriva- 
tion of the very varied and often complex Hexactinellid spicules from 
the regular hexactine or triaxial type. This is particularly difficult 
where more than six rays arise from the centre, but in 1887 Schulze 
showed how these forms might be due to a deep cleavage of one or more 
of the main rays of an original hexaster. Still more difficult are the 
eight-rayed discoctasters of certain species of Acanthascus and Bhabdo- 
calyptus. Schulze’s ingenious interpretation is that each of the main 
rays of an original hexaster divided into four, and that these coalesced 
in threes, thus resulting in an apparent octaster. He also discusses the 
peculiar pearl-like spherules occurring in Pheronema giganteum. 
New Sponges.f — Mr. E. Topsent has had his researches at Roscoff 
and Banyuls rewarded by the discovery of several Sponges, some of which 
are new to the localities, and others quite new to science. From Roscoff 
there come, of the latter, Bubaris constellata and B. gallica ; Pocillon 
and Batzella are suggested as new genera for Myxilla ( Pocillon ) implicita 
and Haliciiondria inops respectively. The new species from Banyuls are 
Dendrilla cirsioides , Darwinella intermedia , Halisarca sputum , Beniera 
parietalis, B. Jlavescens, B. fulva , Gellius Lacazei , Stylotella Marsillii, 
Myxilla versicolor , Stylosticlion jibulatus , PilocJirota Mediterranean and 
Stelletta stellata. Prosuberites is a new genus of delicate Clavulida with 
no microscleres instituted for P. longispina [«’s], and P. rugosus spp. nn. 
A fuller account is given of a new generic type which the author calls 
Besmanthus , a representative of a new family — the Desmanthidae — of the 
Hoplophora triaenosa, than was possible in 1889. The sponge-fauna of 
Banyuls is remarkable for its wealth in Hexaceratina. 
Protozoa. 
So-called Excretory Granules of Infusorians.^ — Hr. W. Schewiakoff 
has studied the doubly refractive granules or crystals which occur freely 
* SB. K. Preuss. Akad. Wiss., 1893, pp. 991-7. 
f Arch. Zool. Exper. et Gen., i. (1893) pp. xxxiii.-xliii. 
% Zeitschr. f. wiss. Zool., lvii. (1893) pp. 32-56 (1 pi.). 
