NATJTILOIDEA. 
174 
Horizon. Cincinnati Group (= Lower and Middle Bala?). 
Locality. Cincinnati, Ohio. 
Eepresented by a single imperfect fragment, presented by J. N 
Pearson, Esq. 
Actinoceras capitolinum ?, Safford. 
1869. Orthoceras capitolinum, Safford, Geol. of Tennessee, p. 290, 
pi. G 3. f. 1 a-c. 
Sp. Char. The only description of this species is in these words — 
“intermediate in character between Bigsbyi and anceps” (the 
Gonioceras anceps of Hall). The figures represent a fragment of a 
large Orthoceratite with strongly waved, approximate septa, large, 
marginal siphnncle, and subtriangular outline ; the latter probably 
due, at least partly, to pressure or weathering. 
A portion of a siphuncle is figured, and numbered 1 c ; but the 
description of the plate runs, “ Pig. 1, a-6,” without any notice 
being taken of “ 1 c.” 
The fragment of a siphuncle representing Safford’s species in the 
Collection is doubtless identical with the one figured, and a label 
accompanies the specimen bearing upon it the same name and loca- 
lity. But it is not conclusively shown by Safford that this siphuncle 
belongs to his species capitolinura, though the inference in favour 
of that view is strong. 
Horizon. Trenton Eormation, Hashville Series ( = Bala Limestone 
Group). 
Locality. Nashville, Tennessee. 
SILIJEIAN SPECIES. 
Actinoceras baccatnm, H. Woodward. 
1868. Actinoceras haccatum, H. Woodward, Geol. Mag. vol. v. p. 133, 
pi. viii. 
Sp. Char. Shell a little curved, perhaps by distdrtion. Section (?). 
Eate of increase about 2 in 13. Septa strongly concave, as seen 
in longitudinal section ; distant rather more than ^ the diameter. 
“ The fossil has been fractured so as to remove the upper surface, 
exposing seven perfect and two fractured beads of the siphuncle, 
and giving evidence of ten septa ; the chambers formed by which 
remain partially hollow, and are partially filled by calcareous 
spar. None of the exterior wall is visible from which the nature 
of the ornamentation of the shell, if any, might have been ascer- 
tained. . . (Woodward.) 
