780 THE PALEONTOLOGY OF MINNESOTA. 
[Cameroceras, sp. 
This species is readily distinguished by its close air-chambers, regular sutures 
and the subcentral position of the sipho. 
Formation and locality.—The larger of the specimens here figured is from the Galena horizon, two 
miles northeast of Spring Valley, Minnesota. The smaller specimen is probably from the same horizon, 
but its precise locality has been lost. 
Museum Register, No. 140. 
CAMEROCERAS, Sp. 
PLATE XLIX, FIG. 1. 
A single long fragment of a slender sipho, 378 mm. in length, 45 mm. in its 
‘circular cross-section at the larger end, has very broad septal funnels, and these make 
but slightly oblique or undulating ridges about the sipho. These are characters in which 
the specimen is quite unlike anything heretofore described. The directness of the 
septal funnels indicates a subcentral position of the sipho, while the length of the 
funnels is much greater than observed in other species. The length of these 
funnels is from 18 to 20 mm. and they are seen to very considerably overlap each 
other. 
The specimen indicates a distinct species of large size, though this example of 
the sipho constitutes our present knowledge of it. 
Formation and locality.—In the Trenton limestone at Cannon Falls, Minnesota. Collection of W. 
H. Scofield. 
CAMEROCERAS, Sp. nov. 
PLATE LI, FIGS. 5—7. 
Among the figures given by Bigsby in his work on the Geography and Geology 
of Lake Huron* is one which shows in section a Cameroceras with large marginal 
subtriangular sipho. No uame has been applied to this American species, though 
the peculiar shape of the sipho indicates a form unlike any which bear names with 
us. Holm has described a species of this character from the Lower Silurian of 
Esthland (Endoceras gladius.)+ 
The specimen figured upon plate u1, figs. 5—7, is a very characteristic example 
of one of these bodies, having one side broad and flat and the other broadly rounded. 
The siphonal funnels on this cast are broad and distant, distinctly curved 
upward on the flat side, but regularly transverse on the rounded surface. From 
Bigsby’s figure we infer that in their normal position in the shell these siphones 
were submarginal, had their curved surface towards the conch and their flat side 
inwards. 
Formation and locality.—The specimen here figured is from the Trenton limestone at Zumbrota 
Goodhue county, Minnesota. 
Museum Register, No. 3399. 
* Trans. Geolog. Soe. London, vol, i, pl. 26, fig. 1. 1824. 
+ Loc. cit., p. 13, pl. 2. 
