MR. HANCOCK ON A SPECIES OF HYDRA, ETC. 405 
Fig. 7.—Enlarged view of a portion of the polype of P. procumbens exhibit- 
ing reproductive system: a, cesophagus; 6, stomach; ec, intes- 
tine; d, supposed ovary with the egg, e, attached ; 4, membranous 
envelope of the egg; g, lower filament supposed to be connected 
with the reproductive system. 
Prats VI. 
Fig. 1.—Polypidom of Paludicella procumbens slightly enlarged. 
Fig. 2.—A portion of ditto much enlarged, exhibiting two or three series 
of cells. 
Fig. 3.—A patch of Plumatella Allmani magnified two times, comprising 
several polypidoms. 
Fig. 4.—Two or three polypidoms of ditto more highly magnified, exhibiting 
the polypes exserted and the envelope of the originating egg a a. 
Fig. 5.—A single cell of same still more highly magnified: a, keel or ridge 
on the upper surface of cell. 
Fig. 6.— Plumatella punciata five or six times magnified, exhibiting polypes 
exserted: a, envelope of originating egg. 
Fig. 7.—Three cells of ditto more highly magnified and more produced than 
usual, with the polypes exserted. 
X VIII.—Wotes on a species of Hydra found inthe Northumberland 
Lakes. By Aupany Hancock, Esq. 
[Read Wednesday, December 12th, 1849.] 
On visiting the Northumberland lakes, last August, for the 
purpose of prosecuting my inquiries respecting the freshwater 
Ascidian Polypes, I took a very beautiful Hydra, abundantly in 
Bromley Lough. On a subsequent occasion, numerous specimens 
of the same species were also obtained in Crag Lough. They 
were found associated with the various Bryozoa that inhabit these 
waters, adhering to the under side of stones which lie scattered 
by their margins, and in situations where there was neither mud 
nor vegetation. From the peculiar character of the locality, so 
different from that of the usual habitat of the Hydro, I was in- 
duced to examine the specimens with great care, and find that 
