38 QUARTERLY CHRONICLE. 
and we shall content ourselves with a description of its ex- 
ternal form and appearance. 
The worm, which from the figure strongly resembles a 
Gordius, has a cylindrical body about half a line thick, and 
more than a foot long. When viewed alive with the naked 
eye or a pocket lens, it is at once seen to present all the 
characters of a true Annelid. The body is divided into very 
numerous segments, of which the most anterior forms a pointed 
‘“head-lobe,” in which lies the upper portion of the nervous 
ring, and beneath which lobe is placed the mouth. The an- 
terior or cephalic extremity, except just at the point, is less 
attenuated than the posterior or caudal, nor is it so much 
tinged with red; whilst in the rest of the body the trans- 
parent walls allow the numerous red blood-vessels to be seen 
through them. There are four rows of setz on the sides and 
ventral aspect, each segment presenting on either side a larger 
seta, which is placed quite on the ventral aspect, as in the com- 
mon earthworm, and a smaller one, which might, from its posi- 
tion, almost be termeddorsal. Everysegment, except the cepha- 
lic and the penultimate and ultimate caudal, are thus furnished. 
In the middle portion of the body the ventral setz some- 
times occur in pairs on either side, but more usually only 
one is met with. The sete themselves have a slight sigmoid 
flexure, with a slight enlargement in the middle. The free 
end is blunt and straight, whilst the other is usually sharp- 
pointed and sickle-shaped. According to Schlotthauber, the 
proper habitat of the worm is moist earth; but according to 
Leydig’s observations it would seem to be truly aquatic, or 
at any rate to require exceedingly wet mud for its abode. 
In the remaining part of the paper numerous interesting 
observations will be found relative to various pomts in the 
organization of other Annelids, and especially of Lumbricus 
and Hirudo. 
5. “On the Epidermoid Layer of the Frog’s Skin,” by Dr. 
M. Rudneff, of St. Petersburg.—In his investigation of this 
structure the author employs a weak solution of nitrate of 
silver (1 to 1000), in which the swimming membrane of the 
frog is immersed for a quarter, or at most half, an hour, when 
the animal, having been rendered motionless by the adminis- 
tration of a few drops of alcohol, the microscopic examination 
is proceeded with. By this procedure the author is able to 
define accurately the outlines of the epidermic cells, which 
are marked by black lines, and has discovered the existence, 
in the intercellular spaces, of bodies having, at first sight, 
the appearance of cell-nuclei, with which it is probable they 
have hitherto been confounded, but from which the bodies in 
