390 The American Geologist. December, 1902. 
It thus is intended to be a complete compend and vade mecum for 
ready use by lecturers and writers and for the independent student 
who desires to investigate any geological subject — at least so far as 
the same may have been already investigated and published by others. 
N. H. w. 
Bidrag till Kannadomen om Trilohitcrnas Byggnad. af. Joh. Chr. 
Moberg [Aftryck ur geol. foren i Stockholm forhandl Bd. 24. H. 
5, 1902.] 
From a fine example of Nileus armadillo Dal. the author is en- 
abled to show the point of attachment of the muscles of the antennae, 
hypostome, epistome, and several limbs of this species. He also re- 
marks upa.T the nature of the compound eyes which have 3-4,000 
facets. In this connection he takes exception to the opinion of the 
late G. Lindstrom that the "maculae" on the hypostome carry organs 
of vision, and that the earlier Olenidae were blind. 
Dr. Moberg compares the system of radiating canals in front of 
the eyelobes and glabella in the Conocoryphidae with the liver im- 
pressions in Limulus, and refers to the presence of these radiating im- 
pressions in Elyx and Harpides, and even in the Olenidae. He re- 
marks on the importance of an organ which is plain in a few blind 
forms, but has left no trace in the majority of the trilobites. 
Considerable space is given to the description of a problematical 
organism apparently related to the graptolites. The paper is illustra- 
ted by one text figure, and a plate showing the head of Nileus arma- 
dillo and the problematical graptolite. G. f. m. 
Animals before man in North America, their lives and times. By Fred- 
eric A. Lucas, Nov. 1902, pp. 1-291, 6 full page illustrations and 
64 text figures. Appleton & Co., Price $1-25 net. 
A year ago, Mr. Lucas presented in popular form some of the as- 
certained facts of "Animals of the past" as they probably appeared 
in the flesh, and of their habitations. This book has been well re- 
ceived and is now supplemen.ted by the one cited above. In the ear- 
lier work, the author dealt with extinct vertebrates, and these were 
described in groups according to affinity or association. In the present 
account both invertebrates and vetebrates are treated and the species 
are arranged chronologically, but not strictly so, thus enabling the 
writer to more readily keep alive the interest of the reader. About 
80 pages are devoted to introductory matter and the invertebrates, 
while the balance of the book treats of the vertebrates with which 
Mr. Lucas is entirely familiar. Some of the chapter headings are 
"How the history of the past is read," "The era of invertebrates," 
"Great salamanders and their associates," "Dragons of sea and air," 
etc. 
Mr. Lucas, among American scientific men, stands nearly alore 
as an author endeavoring to popularize some of the many intensely 
interesting facts concerning the geological antiquities dug out of the 
earth bj- paleontologists. How successful his books are to be with 
