i 
ZOOLOGY. 427 
Natural History, March) it is stated that so slight are the oscilla- 
tions of temperature in the polar sea above the parallel of 70°, 
(ranging between 32° and 36° Fahr.) that the marine animals of 
Greenland are in just as favorable a position as the -animals of 
the tropical seas, where, as observed by Dana, and others more re- 
tently, the temperature of the surface and the bottom at 22 fath- 
oms was identical. 
“ I suppose that the nearly uniform temperature in which the 
high northern marine animals live is one of the chief causes of the 
considerable size by which, according to numerous observations, 
they are ima from individuals of the same species in 
temperate regions; for at the bottom of the icy sea, species which 
from their nature can ome in a low temperature, are but little if 
on temperature) than in individuals of the same species ich: in- 
habit, for example, the middle and higher regions of the North Sea 
est temperatures of the water amount to 10°-15° R. (=22°-5-383° 
“15 F.), or sometimes even more, as has been ascertained by H. A. 
Meyer, for various points in the western basin of the Baltic, ay tel 
myself for two places in the North Sea off the German coas 
A Worm wire Externat Ovarres.—In the same paper Prof. 
Moebius figures and describes a new genus of chætopod worms 
_ With external ovaries from the eighteenth segment onwards: they 
are situated below the branchiæ, and at the boundary between 
the two segments. Within the body-wall in the same segments are 
also eggs. The worm is named Leipoceras uviferum. It is the 
only worm. known which has external ovaries. In a notice in the 
Same journal it is stated that Moebius has discovered that another 
worm (Scolecolepis cirrata Sars) carries its eggs in pouches like a 
Swallow's nest, along the hinder segments of the body. Many Poly- 
chætous worms bear their eggs in sacs attached to the ventral sur- 
face of the body (e. g., Autolycus prolifer Mill.). One (Syllis 
` Pulligera Krohn) carries them in the shorter dorsal filaments of its 
feet, while in Spirorbis spirillum, the eggs are carried in folds of 
the skin, developed in the peduncle of the operculum, with which 
it closes its tube. 
A REMARKABLE BEETLE PARASITE OF THE Breaver.— Dr. Le- 
Conte describes, in the “Proceedings of the Zoological Society of 
