ZOOLOGY OF HYLTON DENE. ~ 99 
sive lagoons which, during the Carboniferous period, supported 
the rank vegetable growths now fossilized in our coal-measures. 
To the paleontologist it must be a matter of considerable interest 
to note the association of species in such localities, and I think 
enough has been said to show that considerable caution should 
be used in pronouncing upon the saline or fresh water nature of 
any deposits merely from the nature of the animal forms which 
they enclose. Judging from analogy, however, (if our own 
island may be taken as a type) we should suppose that any 
great luxuriance of vegetable growth must be indicative of fresh- 
water conditions. We uniformly find in the saline portions of 
these marshes a peculiarly dwarfed and stunted vegetation, 
while as we recede from the salt-water influence it often assumes 
a rank luxuriance, putting on a character quite as much in 
accordance with the vegetation of the coal period as can be 
expected in these degenerate days. 
Group 1. 
Alderia modesta, Praniza sp. 
Limapontia depressa, Temora velox. 
Cythere pellucida. 
Palzmon varians. 
Crangon vulgaris, Annelida. 
Orchestia littorea. Foraminifera. 
Gammarus locusta. 
Corophium longicorne. Vaucheria velutina. 
Sphzroma sp. Oscillatoria littoralis. 
Group 2. 
The same as the above, omitting Alderia and Limapontia, and adding 
Tachidius brevicornis (a minute Entomostracan). 
Group 3. 
Limnea peregra. Cypris monacha. 
Plumatella repens, Candona lucens. 
Paleemon varians. Notonecta, Annelids, &c, 
Mysis vulgaris. 
Corophium longicorne. Callitriche platycarpa. 
Cyclops quadricornis. Potamogeton natans, 
Cypris gibba. Various Alge. 
Cypris aculeata, 
M 
