RESTORATIONS OF DEVONIAN CEPHALOPODS 467 
Gomphoceras breviposticum Whitfield 
(Fig. 13) 
Gomphoceras breviposticum Whitfield: Geology of Wisconsin, Vol. IV (1873- 
79), p- 339, Plate XXVI, Fig. 15. 
Description—‘‘Shell rather below medium size, very rapidly expanding 
from below upward, the rate of increase more rapid toward the base of the outer 
chamber than in the earliest stages of growth, and a 
again decreasing in the same rate to near the middle of 
the chamber, and gently contracted above to the aper- 
ture. The rate of increase in the type specimen in a 
length of two inches below the point of greatest 
diameter, is from a little less than five-eighths of an 
inch to one inch and seven-eighths; septa moderate, 
those preserved being about one-eighth of an inch 
apart, siphuncle lateral in the specimen; aperture 
sharply sinuate on one side, at a distance of one-fourth 
of the circle from the position of the siphuncle. No 
evidence of the lobed contraction of the aperture, as 
in the Silurian examples of the genus, exists.”? The 
siphuncle is on the dorsal side. 
It is possible that G. 
jusijorme Whitfield and Fic. 12.—Restoration 
G. Wrevigosticum Whit. piste ot Corte 
field are of the same ; Le 
species. The differences in the chamber of 
habitation may be due to age. The shells are 
Fic. 13-—External almost identical in size, in the depth of the air 
view of the chamber of 1 is aan Gah 
Habitation and avon  CHamibers, an e margin of the aperture. 
chambers of Gompho- Locality.—Milwaukee Cement Quarry, Berthelet, 
ceras breviposticum whit-  Wis.; ‘Whitefish Bay, near Milwaukee.” 
field. It is possible that 
this species is a young Gomphoceras||fusiforme Whitfield 
form of G. fusiforme. (Figs. 11, 12) 
Gomphoceras (?)ffusijorme Whitfield: Geology of 
Wisconsin, Vol. IV (1873-79), p- 338, Plate XXVI, Fig. 16. 
Description.—‘‘Shell rather below a medium size, very moderately expanding 
from below upward to near the middle of the outer chamber, as seen on the type 
specimen, about which it again decreases to the aperture somewhat more abruptly 
than below. Section circular, or very nearly so, the slight flattening of the speci- 
men probably due to compression. Septa not distinctly defined in the specimen, 
but apparently about one-sixteenth to one-twelfth of an inch apart, and but 
