lieview of liecent Gei>logical Literature. 123 
The American TertUirij Aph'uhv, with a list of the known xpeeiex and ta- 
hlex for their determination. H^y Samuel H. Scuddek. (Thirtconth An. 
Rep., IT. S. Geol Surv, Part 11, pp. 341-:?()r), with plates rii-cvi.) Tliii-ty- 
two species of plaiU-lice. representitig fifteen genera, all regarded as 
distinct from any now living, arc found in 1'ertiary strata at Florissiint 
In Colorado, (ireeii River in "Wyoming, and Qiiesnel in British Colum- 
bia. Though one might suppose, as the author remarks, that the deli- 
cate, gauzj- texture of the wings and the softness of the bodies of these 
insects would scarcely permit their pre,servatioii in the rocks, they an- 
so plentiful at the locality first named that it has yielded more than a 
hundred specimens which have been examined by the author. As a 
whole, these Tertiary genera and species differ most remarkably from 
those of the present day in the great length and slenderness of the stig- 
matic cell of the wings. In the plates the fore wings of all our known 
fossil species are figured on an identical scale, reversed when necessary 
to represent all of them as left wings, and with deficiencies in the out- 
lines and neuration supplied by conjectural dotted lines. Besides Ter. 
tiary Aphid a^. in Europe, two or three specimens of Mesozoic age have 
been found in England: hut these mostly are allied to present genera, 
not- having tlie exiraordinary features of the American fossil forms. 
w. I . 
(Jraaitc.s and ijrccnstonex: a iSeries (f tablet for .studoii.s <f petroloyi/. By 
Fkank Rutley. (8vo, 48 pp.; London, Thomas Murby. 1894.) The first 
of the tables is a tabular classification of eruptive rocks, in which the 
essential minerals of each rock are placed witii the name. Following 
this the various rock structures are defined, and a short descri|)tion of 
each rock species is given, the description including not much more than 
its place in the scheme of classification, the structure and the essential, 
accessory and secondary constituents. The last tables are determina- 
tivi' mineralogical ones: they ditTer from ether tables of this nature in 
that chemical formuhe and specific gravities are omitted, and the ta- 
bles are cleared of other matter which does not relate to simple micro- 
scopic investigation. This little book will prove useful to students and 
teachers; one of the features which especially commends it is its easily 
accessible anil coniMse descriptions of the various rock species. 
r. s. (J. 
On the t/anded .•<tn/rttire (f .some IWtiari/ gabbro.s in the Ixle of Skye. By 
AiuiiiBALD (iEiKiE and J. J. H Tealt.. (Quart. .Tour. Ceol. Soc, vol. 
oO, pp. ()4.5-().}n, pis. 2(5-28, Nov., 1894.) Banded structures are known in 
basic igneous rocks from several localities, perhaps the best developed 
instances being in the gabbros and anorthosites of the .Vdirondacks, of 
Canada, and of the Lake Superior region. In the gabbrcjs of the Isle of 
Skye this structure, as shown by the descriptions and photographs which 
accompany the paper, attains a remarkable degree t)f perf(>ction. These 
banded gabbros are coarse-grained rocks composed of pyro.xene, plagio- 
clase, olivine and titano-magnetite; the banding is due to a variation in 
the relative proportions of these four essential constituents, the ligliter 
