312 lite A)iiericun Geoloyiat. Novfinber , 1895 
«jf late yeais, fossils ol' this fdruuition from the state of Wisconsin or its 
vicinity have been at a great disadvantage from the diflBculty in getting 
clear conceptions of important species from their brief preliminary de- 
scriptions. This embarrassment has especially been felt by the workers 
who have recently been engaged in the preparation of the volumes on 
the paleontology of Minnesota, and probably they will lament most 
loudly the late appearance of these illustrations while rejoicing that the 
unfulfilled promise of the state of Wisconsin to Prof. Hall has been so 
well redeemed by Mr. Whitfield. 
The species considei-ed are all of Trenton age with one exception 
{Melocrinus nodoHUH from Devonian drift) and the generic determina- 
tions are wholly those of Hall, except where the author had himself in- 
troduced a generic term, CaWnhamnopsis, based upon one of these 
species, OJdlimnia frat'tcnsa Hall. Mr. E. O. Ulrich's generic designa- 
tions for the Lamellibranchiata are not recognized and a considerable 
numbei' of that writer's species described in his report for the paleon- 
tology of Minnesota are here included in the synonymic lists. The work 
maintains the magnificent proportions established by the first number 
of these memoirs, and the plates (with the exception of the first, which 
is a photo-engraving representing certain algous fossils, a part of which 
the author had described in another paper) are exquisite examples of 
lithographic drawing and printing. j. M. c. 
Ammonite n-Brnt init Apti/chm in der Withtikdiamer von Oppelia 
steraspis Oppel sp. By R. Michael. (Zeitschr. der deutsch. geolog. 
Gesellsch., vol. xlvi, pp. 697-702, pi. liv, 1895.) The author describes a 
fossil of notable interest to the paleontologist. In the body-chamber of 
an ammonite, whose aperature is closed by an aptychus in nearly its 
normal position, is a cluster of some sixty minute aptychi with remnants 
of diminutive shells. The specimen suggests some important facts 
which are duly emphasized by the author: that the brood of the am- 
monites after Vjecoming free from the ovisac are carried about for a time 
in some part of the haVjitation-chamber; that the aptychus or opercu- 
lum is developed very early in the life of the animal and hence its func- 
tion is of serious importance to the organism. The specimen is from 
Solenhofen. j. m. c. 
Revision, of the Foiinxi of tlw LJuclph Fornuttion of Ontario, witJi de- 
scriptions of a fetv new species, and 
Systematic list, ivith references, of tlie Fossils of the Hudson River 
or Cincinnati Formation at Stony Mountain, Manitoba. By J. F. 
Whiteaves. (Geological Survey of Canada, Palaeozoic Fossils vol. .3, 
pt. 2, pp. 45-128, pis. 9-15. Sept.. 1895.1 Since the first description 
of fifteen species of fossils from the Gueljjh ijy Hall in 1852, and twenty- 
one additional s])ecies by Billings in 1802 and 18(55. further contribu- 
tions to the fauna have been quite desultory. The dolomitic character 
of the rock and the condition of preservation of the fossils are such that 
fine cabinet specimens are rarely obtained and their study is somewhat 
difficult. "Of late years particular attention has been given to the col- 
