Geology and Natural History. 79 
i in Geology, in Harvard sei el 196 pp., large 4to, withe 
lates. Boston, 1881. (James R. Osgood & Co.)— —The plan of 
ei series of which this volume is 2s fin st is to nat illustra- 
tions of prominent subjects in geology—Glaciers, Mountains, 
Volcanoes, Earthquakes, etc., as far as possible from pho tographs, 
and accompanying text iving “a connected i of the more 
bisa Knots and theories that belong to each cation ” 'The vol- 
me w has been issued, on Glaciers, is exceedingly well adapted 
for its murpose. Its illustrations desgies nt some of the most char- 
4to‘size, that exhibits all details in perfection. Among them are’ 
the Glacier des Bossons, de Taléfre from the Jardin, the Aletsch in 
several views, du Géant, and others, in the Alps, with some from 
the Himalaya, Norway, ete. Be sides these, several plates are 
devoted to other Glacial phenomena, and some to those of the 
Glacial era, fie donc the American. The subjects are happily 
chosen for instructiveness, and the beauty of the plates is remark- 
able. ait xt gives an excellent general review of the subject 
of Rene ay modern and ancient, with many important descriptive 
details. It discusses Croll’s theory of the origin of glacial cold, 
with criticisms, and also other se on the Subject ; treats of 
mentioned beyo nd. The volume is’a very valuable one tee both 
instructor and student. 
7. The Trilobite New and Old — Relating to its eew: 
ization; by C. D. Waxcorr. Bull. p-. Zool., vol. viii, No. 1 
—Mr, Walcott here presents the oe of his semarkable cpa 
tions of Trilobites, with full — on six plates. The 
species examined were Ceraurus pleurexanthemus, Calymene 
senaria, and Asaphus patyeephadsa The results show, beyond 
a ii the existence of a series of jointed organs about the 
organs, looking as if spiral, and supposed by the author to be 
branchial in — A “restoration” of Calymene senaria is 
given on plate vi. The series of legs in this “argos looks 
very aeabeea, for, if so distinct in the animal, it seems to be 
incomprehensible that such dissections should have ie needed 
for their discovery. A series of distinct ambulatory legs on a 
ha Trilobite should have been large and stout, and could 
thorax and pees extrem mity, W which have the appearance of 
aving been thin or membranous, are merely subdivided and 
thickened portions of the outer ventral shell, which served as 
attachments for thin membranous articulated appe: anaes such 
as have meohente been attributed to Trilobites. nD 
