254 NATURAL SCIENCE. April. 



Blanchard goes on to say, by its peculiar characters, Mesohdella hrevis 

 (Grube) connects in a remarkable manner the Glossiphonidea with 

 the Hirudinidea. Among the last, it approaches more nearly the 

 Hemadipsinae, 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. Chevreux 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 a specimen of Thcilassochelys caretta were attached Lepas hilliy 

 some young Conchoderma vivgatum, and a PlatyUpas bissexlobata, as well 

 as the following Crustacea : 16 Hyale grimaldii, i Platophium chelono- 

 philum, I Caprella aciitifvons, 4 Tanais cavolinii, and 3 Nautilogvapsus 

 minutus. On another specimen of the same Chelonian, which was 

 abundantly garnished with the Alga, PolysipJionia sertularioides, no less 

 than 259 Hyalae, and several hundreds of Caprettae, 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. 



Gvevilha for March shows a steady improvement on its pre- 

 decessors, especially in point of the illustrations, Mr. Batters makes 

 a new genus, called GilTordia, in memory of the late Miss Gifford. 

 It is made out of Ectocarpns. 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 Ectocarpns 

 is isogamous. A great deal of work tending towards the unsettling 

 of the present grouping of genera in Phacophyceae has been recently 

 done. There are the remarkable observations of Dr. Bornet on 

 Nemoderma Tingitana (Algues de Schonsba; in Mem. Soc. Nat. Sc. de 

 Cherbourg, 1892), and those of Miss Mitchell and Miss Whitting on 



