254 NATURAL “SCIENCE. APRIL, 
Blanchard goes on to say, by its peculiar characters, Mesobdella brevis 
(Grube) connects in a remarkable manner the Glossiphonidea with 
the Hirudinidea. Among the last, it approaches more nearly the 
Hemadipsinz, as much by its mode of life as by the disposition of its 
eyes ; but it is clearly distinguishable from them, as from all the other 
Hirudinidea by the great compression of the somites. The existence 
of this intermediate form shows that these two families are derived 
from a common stock, from which the Glossiphonidea have 
apparently deviated less than the Hirudinidea. 
MM. Cuevreux and De GuERNE have some interesting observa- 
tions on Crustacea and Cirrhipedes commensal on the turtles of the 
Mediterranean in the Comptes Rendu of the Academy of Sciences, 
Paris, 27 Feb., 1893. The observations were made during some 
excursions on the “‘ Hirondelle,” the ‘“ Actif,” and the ‘‘ Melita,” in 
1892. To aspecimen of Thalassochelys cavetta were attached Lefas hilli, 
some young Conchoderma virgatum, and a Platylepas bissexlobata, as well 
as the following crustacea: 16 Hyale grimaldit, 1 Platophium chelono- 
philum, 1 Caprella acutifrons, 4 Tanais cavolini, and 3 Nautilograpsus 
minutus. On another specimen of the same Chelonian, which was 
abundantly garnished with the Alga, Polysiphonia sertularioides, no less 
than 259 Hyale, and several hundreds of Caprette, with other forms, 
were found. 
Messrs. Warne & Co. announce the forthcoming issue of a 
new serial illustrated Natural History, edited by Mr. Lydekker 
The publishers have purchased electros of the greater number of the 
beautiful engravings in the third edition of Brehm’s ‘“ Thierleben,” 
and these, with the addition of coloured plates, ought to make the 
work highly acceptable to the public, altogether apart from the text. 
A large portion of the work will be written by the editor himself, 
but the assistance of specialists in certain groups has been secured. 
Grevillea for March shows a steady improvement on its pre- 
decessors, especially in point of the illustrations. Mr. Batters makes 
a new genus, called Giffordia, in memory of the late Miss Gifford. 
It is made out of Ectocarpus. That old convenient genus is slowly 
breaking up, and in time will occupy a place like that of Conferva—the 
mother of genera. The reason, in the present case is the valid one 
of the discovery, by Dr. E. Bornet, of differences in important parti- 
culars between the male and the female cells, while typical Ectocarpus 
is isogamous. A great deal of work tending towards the unsettling 
of the present grouping of genera in Phacophycez has been recently 
done. There are the remarkable observations of Dr. Bornet on 
Nemoderma Tingitana (Algues de Schonsbce in Mem. Soc. Nat. Sc. de 
Cherbourg, 1892), and those of Miss Mitchell and Miss Whitting on 
