230 The American Geologist. October, 1903. 
island, in the Ottawa river, about seventy-five miles above the 
city of Ottawa. The uplift of this region from the Champlain 
sea level was about 375 feet in the St. Lawrence valley opposite 
the Saguenay, and about 560 feet at Montreal; 150 to 400 or 
500 feet, increasing from south to north, along the Champlain 
basin ; about 275 feet at Ogdensburg ; and 450 feet near Otta- 
wa. The differential elevation was practically completed, as is 
known from the boreal character of the Champlain marine mol- 
luscan fauna, shortly after the departure of the ice-sheet. 
This elevation of the land about the north part of lake 
Champlain, to a greater amount than about its southern part, 
caused the lake, remaining after the sea was drained away, to 
rise southward into a narrow preglacial valley, extending thir- 
ty miles north from Whitehall, closely bounded by steep and 
partly precipitous hills and mountains. 
ON NEW SILURIC CYSTOIDEA, AND A NEW 
CAMAROCRINUS. 
By Charles Schuchkrt, U. S. National Museum. 
The following descriptions of new cystids are taken from 
an extended paper treating of these forms from the Manlius 
and Coeymans formations. As the publication of this paper 
will be delayed six months or more on account of the prepar- 
tion of the necessary illustrations, these descriptions are of- 
fered at this time to enable the writer and others to distribute 
their duplicate material. 
Jaekelocystis n. gen. 
Definition. — Apiocystinae with the theca pyriform or glob- 
ular in outline, rounded oval or four sided in transverse section 
and composed of eighteen plates. These are arranged as fol- 
lows : 
Basal row has plates 4, 1,2, 3. 
Second row has plates 5,' 6, 7, 8, 9. 
Third row has plates 10, 11, 12, 14. 
Fourth row has plates 16, 17, 18, 13, ( 19 absent), 15. 
Fifth row has deltoid 21. It is a very small plate situated 
at the top of plate 18 and between it and 13, and has a compar- 
atively large hydropore, but a madreporite does not seem to be 
