REVIEWS. 643 
tained is similar in general appearance to the clay beds of Mount 
Lebanon and Mount Bolca. The first indication of the existence 
of this deposit was brought by Dr. Jno. Evans, who obtained from 
it a clupeoid, which was described by Dr. Leidy as Clupea humi- 
lis (Proc. Acad. Nat. Sci. Phila., 1856, p. 256). One of the 
blocks contains the remains of two shoals of the fry, probably of 
C. humilis, which were caught suddenly by a slide or fall of cal- 
careous mud, and entombed for the observation of future students. 
S es. 
two may have had a moment’s warning of the catastrophe, as 
they have turned a little aside, but they are the sampon. The 
fry ore from one-half to three-quarters of an inch long an d upw 
e herring, or those with teeth, are chiefly marine, but they run 
into ‘fresh waters and deposit their s pritke in the spring of the year, 
and then return to salt waters. The young run down to the sea in 
autumn and remain there till old ASIA to spawn. The size of 
the fry of the Roċky Mountain herring indicates that they had not 
g left the seorg gene while a. abundance of adults sug- 
gests they were not far from salt water, oe native element. 
To believe, thea, that the locality froin which t se specimens were 
taken was neither far from fresh, nor far can salt waters is rea- 
sonable ; and this pona to a tide, p phir og inlet or river. 
singe of Cyprinodontide inhabit also tide and brackish waters, 
Most of the apeoine of the family as reals s of the genus, are in- 
neria of fresh water ; but they aided especially the cypri- 
nodons proper, prefer still and muddy localities, and, often occur 
in water really salt. This habitat distinguishes them especially 
from Cyprinidæ (minnows and suckers) and pike. Lastly, the 
The material which composes the shales indicates quiet bd goof 
and not such as is usually selected by herring for spawni 
while ‘the abundance of adult Clupeas indicate the proximity et 
salt water. 
This is far from a satisfactory demonstration of the nature of 
the water which deposited this mass of shales, but is the best that 
can be obtained with such a meager representation of species. 
As to =i ee age the indications are rather more satisfactory. 
The genus Clupea ranges from the Upper Eocene upward, being 
to doubt the beds in question being of later than Eocene age, 
genus. 
AMER. NATURALIST, VOL. V. 41 
