642 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
In the spermatozoon a centrosome is present which can be traced from 
the mitosis of the spermatocyte, and ultimately becomes the sperm- 
centrosome of the fertilized egg. It is directly derived from the 
original centrosome of the spermatogonium, and as it takes part in ihe 
mitotic processes is probably one-fourth of this centrosome. 
In the mature spermatozoon the nucleus, centrosome, and Nebenkern 
are enclosed in a delicate cell-membrane, which is apparently the per- 
sistent cell- membrane of the spermatid. 
Synonymy of Starfishes.* — Sig. P. Marchisio maintains that Ludwig 
is in error in placing Echinaster Dorise and Ech. tribulus as synonymous 
with Asterias tenuispina. Of the two first forms he gives a careful descrip- 
tion ; neither has anything to do with A. tenuispina ; but whether they 
are distinct enough from one another to be regarded as separate species 
is left an open question. De-Filippi has distinguished Astropecten aster 
as a new species separable from Ast. squamatus Muller and Troschel ; 
Ludwig has declared the two to be identical, and Marchisio, after a 
careful study of De-Filippi’s type specimens, comes to the same 
conclusion. 
Odontaster and Allied Genera, f — Prof. F. Jeffrey Bell gives reasons 
for uniting with Yerrill’s genus Odontaster , the Gnathaster of Mr. Sladen 
and the Asterodon of Prof. Perrier. The last-named authority places the 
genus with the Archasteridae, Mr. Sladen with the Pentagon asteridae ; 
Prof. Bell agrees with Prof. Perrier. A list of the species of Odontaster 
with synonymy and a few critical notes are added. 
CidarisI cnrvatispinis.j: — Under this name Prof. F. Jeffrey Bell gives 
a description of a remarkable new species of Cidaris from Mauritius. As 
the name implies, many of the spines are curved, instead of being 
straight, and a number are of great length. So far as can be judged 
from a single specimen, the new species belongs to the Dorocidaris- divi- 
sion of the genus. 
Ccelentera. 
Catalogue of Madreporarian Corals.§ — The part before us is entitled 
volume i., but it has the melancholy interest of being the only part 
which will be issued by the same author. Three preliminary papers by 
its author, Mr. George Brook, will have prepared the student for the 
publication of this handsome quarto volume, the photographs in which 
were, at considerable pains, taken by the author himself. An intro- 
ductory essay deals with the history of the genus Madrepora , its mor- 
phology, and the principles of classification. Up to the time of its 
publication about 170 species had been more or less completely 
described; of these a complete revision has been made, the chief 
museums of Europe having been visited for the purpose of consulting 
original specimens. These species have been reduced to 130, but to 
these there have been added 91, of two-thirds of which preliminary 
diagnoses have already appeared. 
* Boll. Mus. Zool. Univ. Torino, viii. (1893) No. 149, pp. 1-6 (1 fig.). 
t Proc. Zool. Soc. Lond., xiii. (1893) pp. 303 and 4 (1 pi.). 
J Trans. Zool. Soc. Lond., xiii. (1893) pp. 303 and 4 (1 pi.). 
§ ‘ Catalogue of the Madreporarian Corals in the British Museum. I. The Genus 
Madrepora.’ 4to, London, 1893, xi. and 212 pp., 35 photo, plates. 
