56 The American Geologist. J"^^'' i^*^-- 
On the other hand, the Enghsh geologists, including Prof. Geikie, 
still include in the Cambrian the next group (Tremadoc) above this 
band, though Brogger and others show that the palaeontological evi- 
dence is against such a decision. The use of the tern Cambrian is 
based on historical usage, and the acceptance of the Arenig fauna 
as the base of the Ordovician. 
Dr. Rudemann, from the conditions at Navy island, in the St. John 
basin, finds evidence (shown by Matthew) that the Dic*-.vonema zone 
should be included in the Cambrian ; but he holds with the continental 
palaeontologists that the division line for the summit of the Cambrian 
should be drawn at the top of this zone. He alludes in terms of ap- 
proval to the work of Ells and Ami on the rocks of the Quebec group 
in the typical region, but he probably misunderstands Ell«' table of the 
divisions in these rocks in attributing the two lower to Lov/er Cam- 
brian on account of remains of Olcncllus thouipsoni. Ells' meanirig 
probably is that the fossils are contained in the pebbles of the con- 
glomerate in division 2, in which case these divisions are not neces- 
sarily Lower Cambrian. 
Rudemann's result would appear not to agree with C. D. Walcott's 
opinion of the limit of the Cambrian (see page 953, fourth paragraph), 
for he, Walcott, would include the Dictyonema zone in 'he lower Or- 
dovician. Moberg has suggested a similar view of this ::one in Scan- 
dinavia, but, as Rudemann has shown, it does not apply in America. 
Dr. Rudemann seems to think it will be possible to divide the Dic- 
tyonema zone in America into two or three sub-zones, as has been done 
for that of Europe in Sweden. 
Three plates are given to show the lithological aspect of the Dic- 
tyonema beds on the Hoosic river in New York. The article is pre- 
liminary to a work on the graptolites of New York by this author. 
G, F. M. 
MONTHLY AUTHOR'S CATALOGUE 
OF AMERICAN GEOLOGICAL LITERATURE 
ARRANGED ALPHABETICALLY. 
ADAMS, GEO. f. (and others). 
Gypsum deposits in the United States. Bull. Xo. 223, U. S. G. S. 
pp. 129, 21 plates, 1901. 
BARBER. W. B. 
On the lainprophyres and associated igneous locks of the Ross- 
land mininsc district, British Columbia (Am. Geol., vol 33, pp. 335- 
347, May, 1904.) 
BERKEY, C. P. 
Mineral resources of the Uintah mountains. (Eng. Min. Jour, 
vol. 77, p. 841, May 26, 1904.) 
