20 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 
Ancestors of our Whales 
Miocene. 
By Prof. J. Z. Gilbert. 
Branch; Mammalia. Order; Cetacea. Sub-order; Mysticeti. 
Family; Balaenidae. Genus and Species not determined, prob- 
ably new. locality. In the mills of Los Angeles city would 
seem a strange place to find whales, and yet when the con- 
ditions are studied there is no reason why whale fossils should 
not be unearthed there. 
In fact the occasion of this preliminary sketch is a find of 
fragments of an ancient whale made in the miocene rocks of 
*Clever Canon; at the east end of East Avenue 33, Los Angeles, 
California. 
Whales Unique. 
Whales seem from the record in the fossils of the rocks to 
have appeared suddenly upon the scene of action and in such 
well differentiated types that a more generalized ancestral 
form must have given rise to them, but such a type has not 
vet been found. 
Whether they came from some gigantic land form and de- 
generated in taking to the water, or whether they had their 
origin in some water form and never developed the pelvie 
girdle and legs of the present mammals is yet a mystery. 
The whales are unique, too, in not being a fading race short- 
ly to become extinct, but this branch of the animal tree is 
green and vigorous yet producing larger and more varied 
forms than have yet appeared. This race might continue for 
millenniums were it not that it is likely to be cut short by the 
intrusions of man decreasing rapidly the numbers and limiting 
the natural supply of food. 
Two distinct types of fossil whales occur: the toothed whales 
(Odontoceti) and the toothless or baleen whales (Mysticeti.) 
Plates I and II; Fig. 1-3. 
The specimens figured and briefly described below were not 
in situ when found, otherwise much more of the skeleton might 
have been obtained. If further finds and investigation bears 
out the present indications this find is interesting since it 
*Named by Harriette Y. Gilbert. 
