EXTRACTS FROM FOREIGJ^ PERIODICALS. 
99 
remarkable that all the examples of it are found collected within a radius of two 
or three leagues only. 
5. SpirulaPeronii. —It is a rare thing to find this common shell with its animal* 
a fact which, according to MM. Robert and Leclenchet, is in some measure 
explained by their having discovered that it is the prey and common food of the 
Physalix^ which swarm in the same equatorial seas. The figures hitherto 
published of the Spirula are incorrect; it is a cephalopode which approaches re¬ 
markably in form to the shell-less Loligo sepiola^ having the shell almost entirely 
imbedded in the posterior part of the body, where there are two natatory ex¬ 
pansions of the cloak. The eye is proportionally very large, and without a lid. 
—Annales des Sciences Naturelles ; as translated in the Mag. of Zool. and Bot., 
Vol. i., p. 414. 
6. Parmacella^ Cuvier. —MM. Webb and Vanbeneden have attentively exa¬ 
mined the American mollusca, reputed to belong to this genus, in the rich 
collection of the late Baron de Ferussac, and the result is, the establishment 
of a new genus ( Peltella ) for their reception, the organic differences between 
them and those of the old continent being so considerable as to justify their 
separation. This division, besides, has the advantage of fixing in a precise 
manner the geographical distribution of the two genera. The Parmacellce 
belong more particularly to North Africa, one species only having been met 
with at the western extremity of Europe, and in one of the warmest regions of 
the Iberian Peninsula. We may then presume, that when the Limacidce of 
North Africa are better known, the group to which the Pharmacellde belong, 
will present a series of species similarly conformed, and replacing in those 
climates the Slugs of our temperate regions. The European species is mi¬ 
nutely described and figured in a late No. of Guerin’s Magazin de Zoologie. 
It was found on the hills of Alcantara, behind Lisbon, feeding on the young 
shoots of Cochlearia acauliSt and is characterized as follows:— Parmacella Va- 
lenciennii, corpore to to fulvo, reticulatim ruguso; concha scutello obvoluta, 
tenui, diaphana, fragili^sima; spirae rudimento instructa, basi motaria amditu 
sinuata.— Webb and Vanbeneden in Mag. de Zoologie. 
• BOTANY. 
7. Reproduction of AuGiE. —The eighth volume of the Societe de Physique et 
cCHistoire Naturelle de Geneve, contains a paper read Dec. 17, 1835, by M, 
Duby, on the propagation of the species of Ceramium. Highly important 
conclusions have resulted from this memoir (the greater part of the materials 
of which were furnished by M. Crouan, a naturalist of Brest), regarding the 
physiology of the Algce, and especially of Ceramium. They may be reduced 
to the following « 
