164 The American Naturalist. [February, 
According to Mr. S. W. Williston the thickness of the Niobrara 
rocks in Kansas have been underestimated. Repeated observations at 
Elkader, in Logan Co., give 290 feet between the bottom of the valley 
and the highest Niobrara frocks. Wells in the vicinity penetrate 40 
feet without passing through the blue chalk. To this, for stratigraphi- 
cal reasons, he adds 100 feet, giving as a minimum 430 feet at a total 
thickness at this place. (Trans. Kansas Acad. Sci., Vol. XIIL) 
Cenozoic.—Mr. C. T. Simpson reports eight species and one vari- 
ety of Unios and six species of other fresh water shells from the drift 
of Toronto, Canada. All the Unios are characteristic forms of the 
Mississippi Valley, and only three have ever been reported before from 
Canada. The fossils were obtained from a bed of sand between two 
glacial beds in a railway cut, 20 or 25 feet above the River Don. Mr. 
Dall calls attention to the important bearing which these fossils may 
have upon the theory of a mild interglacial period, during which these 
Mississippi species attained that region where they flourished for a time 
and were then destroyed by an advance of the ice. (Proceeds. U.8. 
Natl. Mus., Vol. XVI, 1893.) 
Reasoning from the data gathered for a study of the age of the 
extra-moraine in eastern Pennsylvania, Mr. E. H. Williams concludes 
that the total time of the Ice-Age, from beginning to end was sma 
and of so recent a date that the streams have not reached, in all case 
their pre-glacial bottoms, and the exposed rocks have not had time t0 
acquire signs of decomposition or even oxidation. He inclines to the 
belief of but one ice age, and that a short and recent one (Am. 
Journ. Sci. Jan., 1894.) ti 
Mr. Alfred} Bell notes the unique fauna of a post-Tertiary deposit = 
the shores of the Selsey peninsula in Sussex. Over 330 dae 
nearly all classes of organic life have been collected, the series exhibit- 
jog a purely;southern facies free from any northern or boreal forms. ia . 
analysis of the list gives the following result : Non-marine, 8 Mamm 6 
10 Mollusca, some‘fragments of insects and 3 plants. 
Crustacea, 17 Entomostraca, 4 Cirripedia, 4 Annelida, 
216 Mollusca, 10 Polyzoa, 50 Foraminifera, 4 Actinozoa, Alge, 
(Annual Report Yorkshire Phil. Soc. for 1892.) 
The Manus of Hyopotamus.—Among the treasures obtained 
the White River bad lands of South Dakota by the Princeton Mh, 
tion of 1893 was a fine skeleton of Hyopotamus, which was ape i 
Mr. J. B. Hatcher. This specimen presents a number of very 
