984 General Notes. [ September, 
Joliet read some observations on blastogenesis and alternating 
generations in Salpa and Pyrosoma. 
Mollusks—R. Bergh continues in the Verhandlungen of the 
Imperial Zodlogical and Botanical Society of Vienna his elabo- 
rate contributions to a knowledge of the Æolidæ, a group of 
nudibranchs, accompanied by excellent plates. . 
Arthropods.—In his comparative study of the arachnofauna of 
Abyssinia and Shoa, published in the report of the Lombardy 
Royal Institute of Science and Letters, Professor Pavesi describes 
thirty new species of spiders, for one of which (Chiasmopes) he 
establishes a new order. Count Keyserling contributes to the 
Verhandlungen of the Zodlogical Botanical Society, of Vienna, 
the fourth part of his “ New Spiders from America ;” a few spe- 
cies are described from Colorado, the remainder from South 
America. C. Norner describes very fully, in the same Verhand- 
lungen, Analges minor, a new mite living within the quills of the 
hen.—tThe researches on the fauna of the Black sea of Rathke, 
Nordman and others, made as far back as 1823, revealed only 
forty species of Crustacea, and led to the opinion that this sea 
was barren in life of this sort. But 160 species have lately 
been added by a number of Russian observers, of whom the most 
prominent is Bobretsky. Czerniawsky now affirms, says Nature, 
that the Crustacean fauna of a single bay of the Black sea, the 
Bay of Yalta, is richer than that of the whole of the Belgian : 
coast. This fauna was by some authors supposed to: be like i 
that of the northern seas, but in a notice published in the 
last volume of the Mémoires of the Kieff Society of Naturalists, : 
M. Lovinsky points out the close relationship of the Black sea | 
crustacea with those of the Mediterranean sea, the latter having 
its northern forms as well as the Black sea. But’'the Black sea 
fauna appears to be a part of the fauna of the Mediterranean 
basin, slowly modified by the medium it inhabits; this opinion iS 
supported by the kinship of several Black sea forms with big 
of the Mediterranean and the Red sea, and by the richness 
the Black sea fauna in more varieties and in such forms as are 7 
purely local, the prevailing types of the fauna being still the cos” oe 
mopolite ones. The Black sea fauna would thus be but a git 
the Mediterranean fauna, but much impoverished, and modifie¢ 
to a great extent by the variety of local conditions. SA 
Vertebrates. —At a recent meeting of the Berlin Physiologic 
Society, Du Bois Reymond communicated a short notice 1 hark 
letter of Professor Babuchin’s to him, which contains a fact mit 
esting as showing the power of adaptation to their mone a 
that electric fish possess. Professor Du Bois Reymond : toa 
viously calied attention to the fact that the electric eels ané 
lapterurus that live in badly-conducting fresh water shom" 
far as have accommodated themselves to this medium, o 
