SS Th e American Geolog ist. February, 1892 
Jour. Sci. [2], xxxv, 61); Descriptions of fossils from the Yel- 
low Sandstones lying beneath the Burlington limestone at Burling- 
ton, Iowa. (Proce. Acad. Nat. Sci. Phil. Jan. 1863). He also 
published Descriptions of elephantine molars tu the Museum of 
the University of Michigan. (Canadian Naturalist, October, 1863, 
p. 398.) He also investigated minutely the ‘‘Cherry slug,” 
Celandria cerasi, and his report was published in the Proc. Bos. 
Soc. Nat. Hist., Feb. 1865. 
1864. In 1864 he made a detailed study of the ‘Currant 
worm” microscopically and embryologically. The results were 
published in the Detroit Free Press and republished in the Ameri- 
can Journal of Ncieiwee, September, 1864. The following further 
papers were published this year, Fossils from the Potsdam Sand- 
stone of Wisconsin and Lake Superior (Amer. Jour, Sei. [2] 
XXXVI. p. 226); Notice of a Mastodon recently discovered in 
Michigan. Ib. [2] xxxvin. p. 223; Description of a garpike 
supposed to be new (Lepidosteus oculatus), (Proc. Acad. Nat. Sei. 
Philadelphia, Aug., 1864); Geological map of Michigan: On the 
origin of the Prairies of the Mississippi valley (Am. Jour, Sei. 
(2). Xe VID, pp) 332). 
1865. In January, 1865, he delivered an address at Lansing, 
before the Executive Committee of the State Agricultural Society, 
on The soils and subsoils of Michigan, which was published by 
the Committee in pamphlet form. In this he insisted on the 
agricultural value of the -‘pine lands” of the state, and pointed 
out the existence of a large calcareous constituent in the sandy 
soils about Grand Traverse bay. He continued his investigation 
of the fossils of the +*Marshall group,” and published another 
series of descriptions of new species in the Proc. Acad. Nat. Sei. 
July, 1865. About this time his attention was much taken up 
with the phenomena of oil wells, and he was called to many and 
distant places for the purpose of making surveys. He visited 
and studied, in this way, all the oil-producing regions of the 
United States and Canada; and a large number of his reports 
were published by the proprietors in separate pamphlets. He 
wrote numerous articles also on these subjects for the public 
journals. 
It was in February and March of 1865 that the germs of the 
malady which finally caused his death, were made apparent in an 
impairment of his general health and rheumatic pains. On the 
