% 
he ‘ ined by saying, that if certain existing orga 
'e to . . 
CAT al : 
(8.) On the nettling organs of the Hydra, (Ib., p. 119.) 
(9.) New Fossil Mammalia from Missouri, (Ib., p. 121.)—Species : 
—Palzotherium Bairdii, Rhinoceros nebraskensis, Merycoidodon Cul- 
bertsonii, Agriochcerus antiquus. 
The species of Palzeotherium described in this Journal, vol. iii, p. 248, 
Proutii. 
ew Species of Vermes, (Ib., 124.)—-Species :— 
Peloscolex (Leidy) variegatus. Emea (Leidy) rubra. 
Cheetogaster gulosus Anortha (Leidy) gracilis. 
of climate, foo reatment produce specific distinctions. 
Species is defined by Buffon, “a succession of similar individuals 
which re-produce each other.” Cuvier’s definition is near! ; 
domestic species are stronger than those of any species of the same 
genus. The fa or 0 
Succession, constitute’ alone the validity of the species.” 
An objection to these definitions arises from the fact that they apply 
88 readily to mere varieties as to acknowledged species. Certain albino 
- Thave brought together these definitions, int t : 
that naturalists are by no means agreed upon what constitutes a species, 
and secondly, to offer some views of m 
monu ental records, both of Eypt and Assyria, of which we are now 
Happily possessed of the proximate dates. My view 
Into the “ night of time,”’ as dissimilar as we see them now, is it 
€ 
Zoology. Q75 : A 
