204 
NAUTILOIDEA. 
Huronia mixmens, Barrande. 
1870. Huronia minuens, Barrande, Syst. Sil. de la Bolieme, vol. ii. 
Texte iii. 1874, p. 744, pi. ccccxxxv. f. 4. 
Sp. Char. The salient feature in this species, which distinguishes 
it from all others, is the great breadth of the siphuncular segments 
compared with their height, the latter measuring less than half of 
the former. A specimen in the British Museum gives the following 
measurements, viz. : — height of the segment ( = distance between 
the septa) 9 lines ; greatest breadth, measured at the base, 20 lines. 
At least two thirds of each segment is occupied by the swollen rim. 
Nothing remains of the septa. 
Horizon. Niagara Group (Wenlock). 
Locality. Drummond Island, Lake Huron. 
Represented by two specimens, one of which was presented by 
Dr. J. J. Bigsby, F.R.S. 
Huronia persiphonata, Billings, sp. 
1857. Billings, Geol. Suit, of Canada, Rep. 
of Progress for the years 1853-oG, p. 329. 
Sp. Char. “ Elongate, large ; siphon of great size, marginal ; 
strongly annulated in the upper half or two thirds of each chamber, 
and cylindrical or but gradually expanded in the lower third ; septa 
very thin and convex, distant six and a half lines on an average 
when the siphuncle has a diameter of one inch and a half. 
“ The annulations of the siphuncle are, in the two specimens 
examined, a little oblique, the ventral margin being nearest the 
aperture ; a fragment of a siphuncle six inches and a half in length 
tapers from one inch and a half to one inch and a quarter, or at the 
rate of about half a line to the inch. 
“This species differs from 0. canadense\_— H.vertehralis^ Stokes] 
only in its more approximate septa, and appears to have been like 
that, an extremely long, tapering form, with very thin, fragile, 
exterior shell and septa.” 
RemarTcs. The specimens representing this species consist of the 
siphuncle only in a very imperfect condition, but recognizable as 
belonging to Billings’s species. 
I am indebted to the kindness of my friend Mr. H. M. Ami, of 
the Geological Survey of Canada, for a sketch taken from one of the 
original specimens described by Billings. This has been of great 
assistance to me, more especially as the species was not figured by 
its author. 
