136 
The following species of Hydra, was discovered too late to he 
inserted in its proper place at page 11. 
HYDRAIDiE. 
Polypes gemmiparoas, the young pullulating from the body 
of the parent. 
HYDRA. 
Generic Character: Polypes locomotive, single, naked, 
gelatinous, sub-cylindrical, but very contractile and mutable 
in form, the mouth encircled with a single series of 
granulous filiform tentacula. 
COMMON HYDRA. Ilydra Vulgaris. Body gelatinous, 
sub-cylindrical ; tentacula seven to twelve, as long or longer 
than the body. 
Hydra vulgaris, Ellis and Solander’s Zooph., p. 9. Tor- 
ton's Lin., vol. 4, p. 672. Stewart’s Elem., vol. 2, p. 452- 
Templeton in Mag. Nat. Hist., vol. 9, p. 418. Johnston’s 
Brit. Zooph., p. 95, pi. 1. 
Hab. In the Trengwainton ponds, near Penzance. Com- 
mon. 
This, though a rare species in the country is common in all 
parts of the ponds ; where it is to be found on Nitella Irons - 
lucens and other weeds growing there. If the usual des- 
criptions of this Hydra are characteristic of its appearance* 
it would seem as if the one now under consideration was 9 
distinct species. As, however the Hydras are liable to gre®* 
variations both in form and colour the present one has beeu 
refered to the H. vulgaris, as it bears the closest resemblanC 5 
to it. It, appears to be the variety b. grisea, Johnston ; b" 
though the tentacula are longer than the body, yet they are o 
a claret red and not olive green colour. The body is r e "’ 
gelatinous, and ovoid; the tentacula vary in number fro*" 
seven to twelve are long and granular, but vary in leD? 1 " 
and size according to the degree of their contraction. Ij 1 ! 
is one of the creatures on which Trembly performed 
celebrated experimemts. His conclusions have been verif’f 
by subsequent observers. Their powers of supporting " j 
under the most violent injuries arc all but miraculous, ®" 
more nearly resemble the attributes of Milton’s Ang el ’ 
than any reality, 
Vital in every part, not as frail as man 
In entrails, heart, or head, liver or veins, 
Cannot but by annihilating die ; 
Nor in their liquid texture mortal wound 
Receive, no more than can the fluid air. 
