Review of Recent Geoloyical lAterature. 185 
served by Mr. Sardeson in the Shakopee, Oneota, Jordan and Saint 
Lawrence formations of Minnesota and Wisconsin. These notes are 
preceded and followed b\' four and one-half pages of matter devoted to 
subjects as follows: (1) A statement of the object of the paper: (2) an 
enumeration of the lithological divisions of the "Lower Magnesian" and 
"Potsdam" of the upper Mississifjpi basin: (3) general remarks on their 
faunas, in which the author expresses the opinion that the ''Shakopee 
is faunally separate from the Saint Peter above and to a less degree also 
from the Oneota below," and that the Oneota, Jordan and Saint Law- 
rence formations are closely related to each other and faunally distinct 
from the St. Croix sandstone beneath them; (4) remarks on preserva- 
tion of fossils: (5) table showing vertical range of species: (6) list of and 
critical remarks on Lower Magnesian species described from Iowa by 
professor Calvin: (7) list of Lower Magnesian fossijs described by Whit- 
field and A. Winchell and remarks on the same: (8) a statement to the 
effect that the Shakopee fauna is most like that of the "Upper Calcif- 
erous," while '"that of Oneota, Jordan and St. Lawrence is likewise 
comparable to the Lower Calciferous of New York;" and, finally, (9) a 
paragraph devoted to the "biological side of the question," in which we 
find the very true observation that "to associate the species Rapliisto- 
ma leiosornellum, R. lewistonense, R. minnesotense and R. otceni is to 
extend the limits of the genus." From the table showing vertical range 
of species we learn, and this is perhaps the most important fact estab- 
lished in this paper, that all of the seven species found in the Shakopee 
are restricted to that ff)rmation. while of sixteen species found in the 
Oneota, five occur also in one or both of the two formations immedi- 
ately beneath. 
Concerning the various species, especially the Gastropoda, many of 
which are represented in the reviewer's cabinet, we are led to remark 
that Mr. Sardeson seems to have had anything but a clear conception 
of their generic affinities. His descriptions of new species also, consider- 
ing the poor character of the illustrations, are too brief and quite devoid 
of anything like comparisons with previously known forms. Evidently 
he proceeded to name his fossils without comparing them with species 
described from equivalent rocks in other regions. Naturally such work 
is very liable to swell the list of synonyms and it will be extraordinary 
indeed if Mr. Sardeson escapes entirely the responsibility of having pro- 
posed one or more unnecessary names in the paper under discussion. 
One already is evident in his Murchisonia argylentiis, which, with good 
specimens before us, we do not hesitate to pronounce the same as M. 
anna Billings. The ajjical angle of this shell is given by Mr. Sardeson 
as 160°. It should be 15"^ or 16". We assure him also that the l)and is 
not central but lies in the lower third a short distance above the suture. 
The carina or angle forming the lower boundary of the flattened outer 
face of the whorls of his Helicotonia {?) iwccatonicu, as well as the 
shape of the shell in general, is indicative of Trochonema and not Heli- 
cotoma. The species seems to be related to T. exile Whitfield. His 
Raphistoma leicistonense, on the other hand, should have been referred 
