332 The American Geologist. November, 1893 
every suborder known in the fossil state was represented before the 
close of the Lower Silurian era." 
The plates illustrating this report are admirably executed, and give 
usually several figures for each species, some of which appear in one or 
more varieties besides the type. 
The Lower Silurian Brachiopoda of Minnesota. By N. II. Win- 
chelTj and Chables Sohuhert. pp. 333-474, with plates 29-34, and fig- 
ures 21-34 in the text, forming chapter v in the volume before noted; 
June 6, 1893. Without counting numerous subgenera and varieties 
which are noticed in this chapter, it gives descriptions and figures of 
7!) species, under 27 genera. Ten are new species, and a considerable 
number besides are by the same authors, having been described in the 
Am. Geologist for May, 1892. 
In noting the manner of occurrence of these shells in the Trenton 
shales of St. Paul and Minneapolis and other localities thence south- 
ward, the following remarks are given concerning the stages of growth 
often represented: "Much can be accomplished in the discovery of 
young specimens 1 mm. in size up to maturity. These small specimens 
cannot be picked up on the hillsides, nor on the quarry dumps, but 
usually where ad ult examples of a species are abundant, there, also, will 
be found all individuals from the youngest to the mature shells. Col- 
lectors discovering such localities should not fail to carry away a small 
sample of the shale to be washed carefully in a pan until the water is 
colored no longer by the residuum. After drying, what remains should 
be sifted into various sizes to facilitate examination with the hand 
lens. If the sample proves to contain young specimens, it will be only 
a matter of washing and picking to secure of a species a complete 
series of specimens from less than 1 mm. in length to the adult size. 
Such series are of great value in classification, and much yet remains 
to be done in this direction. A great deal can also be learned by local 
collectors in regard to the evolution, introduction and disappearance of 
the species in these shales." The authors follow Hyatt's nomenclature 
in their descriptions of successive growth and development stages: 
and the classification agrees substantially with that presented by 
Schuchert in the Am. Geologist for last March. 
A Mono(jr<i/ih of tJie British Pahvozoic Phyllopoda {PJtyllocarida 
Packard), by T. Hupert Jones and Henry Woodward. Part n, Some 
Bivalved and Univalved Species, pp. 73-124, pis. xiii-xvii. London, 1892. 
(The Pahfontographical Society, volume for 1892). 
Under a grant from the British Association for the Advancement of 
Science, these eminent authorities on the fossil Crustacea, together 
with R. Etheridge, sr., whose name does not appear in this publication, 
undertook, some years ago, the monographing of the British species of 
Pala'ozoic Phyllocarida. After various preliminary papers which have 
taken the form of annual reports to their patron society, and which 
purported to be, in the main, essays toward the classification of these 
