llericir of Rereiif (rt^olixjifdl Lilc.rnfure. HI 8 
lecting of natural moulds of the exterior of shells of Gasteropoda, etc-., 
from this formation, as it has been found that gutta percha impressions 
of such moulds often give much more information about the exact shape 
and surface markings of the shell than can be derived from mere casts 
of the interior." The further light thrown upon the Upper Silurian 
Gasteropoda by Lindstrom's researches in Gotland has made it desir- 
able and practicaVjle to review all the species thus far known from the 
Guelph formation of Ontario. The author now brings together about 
one hundred and thirty species from this horizon, of which six are new. 
The entire numV)er is distril)uted as follows: Corals 12 species, Hydro- 
medusae 6, Brachiopoda 25, Pelecypoda 10, Gasteropoda 51, Cephalo- 
poda 15, and Crustacea 7. The absence of echinoderms and the abun- 
dance of gasteropods are conspicuous features. Among the latter, 
Pleurotomaria and Miirchisonia are the most diversified types. The 
trimerellids are the dominant brachiopods and give a peculiar aspect to 
the fauna. 
In the second paper an annotated list of nearly sixty species is given 
from the only known locality of the Hudson River groujj in Manitoba. 
c. E. B. 
Fauna fosil de la Sierra <le Catorce San Lnin Potosi, y Jo.se G. 
Aguilera. (Comision Geologica de Mexico, Antonio del Castillo, Di- 
rector, Boletin Num. 1, 55 pp., 21 pis.. 1895.) The first memoir of a new 
series of publications l)y the Mexican government is a welcome contri- 
bution to our knowledge of North American Mesozoic geology. In at- 
tempting to establish the existence of the Jurassic as a well defined 
formation in that part of the continent, the evidence of recently discov- 
ered fossils is relied upon. Most of the species considered are descriVjed 
as new, the many and minute comparisons which are made with allied 
forms in other parts of the world is an admirable feature in aiding pale- 
ontologists to better understand the true character of the fauna studied. 
The fossils are for the most part cephalopods, though the brachiopods 
and lamellibranchs are comparatively well represented. Most of the 
material upon which the investigations are based is evidently in a good 
state of preservation, but it is rather unfortunate that better illustra- 
tions were not prepared for some of the forms. With the methods em- 
ployed in the reproduction of the illustrations the details of the highest 
specific and generic importance are largely obscured and in some cases 
entirely obliterated. c. k. k. 
Bureau of Mines of Ontariu, Fourth Report, is'ji. Archibald Blce, 
Director. (8vo, \)\y. vi, 261: maps and illustrations of the Rainy River 
district; Toronto, 1895.) The contents of this volume are: 1. A general 
discussion (pp. 7.31) of the condition of the mining industry of Ontario 
during the year, with particular reference to certain brani-hi'S in process 
of development at present. 2. A chapter (pp. .35-100) on "Gold in Onta- 
rio," with i)articular description of the Rainy Lake gold region, by Dr. 
A. P. Coleman. 3. A compiled account (pp.101-138) by Mr. T. W. Gibson 
of the ''Hinterland of Ontario," Vjy which is meant the region lying be- 
