Helicolimax Lamarckii. 309 
again at pleasure, by a muscle attached to it behind. It is at the base, 
where the tube of the bulb perforates the external pouch, a little up on 
one side, that the orifice of the tube leading from the muscular organ of 
the matrix is inserted. The structure of the whole will be understood 
without difficulty from the figures. At fig. 8 the penis and the pouch 
through which it passes are laid open, so as to shew their structure 
within. 
It is impossible without having an opportunity of seeing living speci- 
mens to understand exactly the limits of inversion of the different parts; 
nor indeed even in Helix does this point seem to have been much studied, 
from the difficulty of doing it with success. I have merely described the 
structure, such as I was able to observe it in specimens preserved in 
spirits, and therefore probably in almost an unnatural state of contraction. 
It remains that I compare the structure with that of the neighbouring 
genera. Mr. Lowe remarks its near relation with Parmacella. To this 
conclusion J hadarrived, independently, from the consideration principally 
of the anatomy. Indeed, in external characters alone, the resemblance 
is too striking to escape notice, and this will be found confirmed by the 
internal structure. De Férussac has long ago remarked the extreme 
resemblance of Parmacella to some Helicolimaces (Vitrine). 
First then, compared with Helix, we find the pulmonary and nervous* 
systems almost identical. The mass of the mouth, tongue, and its main 
retractor muscle are thesame in both. The tooth alone differs slightly. 
With respect to the stomach, there is in Helix a tendency in this part to 
put on the form of a double stomach, insomuch that some authors have so 
described it; the structure in Helicolimazx is only a step beyond this; 
for there is no great difference in the thickness of the coats of the two 
portions, and indeed when the upper portion is fully drawn out, the 
difference is the least possible. Besides in Helix the salivary glands, 
which are very similar to those of the present animal, end just at the 
point where the slight strangulation of the stomach takes place. Iam of 
course not at liberty to assume the similarity of the liver, or position of 
* I did not observe the ganglions under the origin of the wsophagus which 
exist in Heliw (in Hel. aspersa there are two), but this arose perhaps from my 
attention not being directed particularly to that point. 
Vou. V. x. 
