372 General Notes. [April, 
velopmėnt of new genera of beasts of prey began with dog-like 
imals. ; : 
Much more interesting for the purpose of our investigation 
here is the Otocyon lalandii, the spoon-dog of South Africa, so 
called from the peculiar formation of the skull. Its habits show 
an approximation to the foxes, yet as regards dentition it does 
not show this affinity, inasmuch as it possesses 4:4 molars, and 
also shows the most remarkable differences in the relative size of 
the single teeth. As already said, the spoon-dog is, in many 
ways and as regards dentition, shaped after the fashion of the dog 
type, and can thus scarcely be dragged out of this connection, 
and we are compelled to look upon it asa still existing primary 
form of dog. The whole paleontology of the vertebrates shows 
that the many-toothedness of mammals is an inheritance from 
their lower ancestors, and that any increase of the teeth within a 
class has probably never taken place. 
As our dogs, with their 2:2 molars, have no doubt been de- 
scended from fuller-toothed animals, Otocyon must be regarded 
as the still-living representative of the early type of dog, which 
very small frontal depressions, it is, as Huxley says, very di í 
cult not to imagine that these too must be traced to ancestors © 
the Otocyon type. From this species, therefore, we should have 
to derive the two lines which diverge into the fox on the one 
hand, and the wolf on the other. We are supported in this view 
by the observation that the South American Cams eet 
often possesses the fourth molar, and thus shows itself to 
another remnant of the primary form. A fourth supernumerary 
molar of this kind is not a monstrosity or pathological phenome 
non, but an atavism or reversion of the same sort as the so 
_called wolf's tooth in horses, which was explained as a premolar 
which existed in the primary genus Anchitherium. i a 
- Hence the key to the derivation of all the dog tribe is to 
found in their relation to the spoon-dog. 
ey GEOLOGICAL News.—Si/urian.—S. G. Williams, in a communi- 
= cation to the February number of the American Fournal of Sci- 
ence, states that rocks of the Lower Helderberg periód, including 
all above the water-lime group, are represented in New Yor i 
far west as Cayuga lake, by limestones not less than sixty-five tee! 
‘thick, containing an unmistakable Lower Helderberg fauna. 
Though fossils are rare in Cayuga county, fifteen species 
‘the others all belong to Lower Helderberg species. 4 per 
_ them are two species of Strophodonta, RAyn honella semiphica® r 
—  Stromatopora (most abundant of all), a Favosites and a Zap 
_ rentis. | 3 
have 
-~ been found, two or three of which are as yet undescribed while 
Ea AN eee oii KAPE S EA ae : 
ee ee ey ee ee a a 
