38 The American Geologi$t. January, 1894 
Dr. Lapham was a prolific writer for the press, and for encyclopaedic publications. 
One of his earliest articles was On Farmers' Libraries, in The American Farmer, 1832 ; 
another on Agriculture iu Ohio, in the Genesee Farmer, 1833; in the Milwaukee Senti- 
nel for Sept. 3, 1849, he had an important article on Discovery of a Tide in Lake Michi- 
gan ; the article on Wisconsin, in Appleton's American Encyclopaedia (1859-1862) was 
by him, written at the request of Governor Haney ; in The Chicago Tribune, 1873, he 
wrote on Supposed Subterranean Sources of the Waters of the Great Lakes ; in the 
Milwaukee Republican, March 1, 1852, he wrote of The Geology of Waukesha. These 
are only a few of his important newspaper articles, but show the scope of hie work. 
His map of Milwaukee, first issued in 1845, was published annually until 1861 ; his map 
of the state, first issued in 1849, was republished in 1850, 1853, 1854 and 1857. He pub- 
lished a geological map of Wisconsin in 1855 and 1869 ; and the state map in the Legis- 
lative Manuals, 1865-75, was his work. 
ON THE MODE OF OCCURRENCE, AND THE 
STRUCTURE AND DEVELOPMENT OF 
TRIARTHRUS BECK1.* 
ByC. E. Beecher, New Haven, Conn. 
The presence of antenna 1 and other appendages on a trilo- 
bite from the Utica Slate was announced in May, 1893, by W. 
D. Matthew. f The specimens were discovered by W. S. Val- 
iant, J near Rome, New York, where they occur in a fine- 
grained carbonaceous shale. It was apparent that specimens 
preserving organs so delicate as antenna? ought to show, in 
addition, other anatomical features which would be of great 
assistance in determining the zoological position of the Tril- 
obita. With this object in view, and with the assistance of 
Prof. Marsh, a collection was made for the Yale Univer- 
sity Museum. From this material, it is hoped that the re 
maining details in the structure of this important fossil may 
be made out. The preliminary examination of the specimens 
shows a number of new and remarkable structural features, 
some of which will be briefly noticed here. It was also possible 
for the writer to make observations in the field, which fur- 
*Abstract of a paper "On the Structure and Development of Trilo- 
bites," read before the National Academy of Sciences, November 8, 
1893. 
|"On AnteDna? and other Appendages of Triarthrus Beckii." Read 
before the N. Y. Academy of Sciences, May, 1893. Published in Ameri- 
can Journal of Science, vol. xlvi, pp. 121-125, August, 1893. 
JMr. Valiant informs me that he found the first specimen showing 
antenna? in 1884, but it was not until 1892 that other specimens were 
obtained by him and M. Sid. Mitchell fully establishing the discovery. 
The specimens sent to Columbia college were collected by W. S. Valiant 
of Rutgers college. 
