NORTH AMERICAN GRAPTOLITES 309 
SUPRA-ORDOVICIAN—Continued 
Upper Silurian Devonian Hove 
Genus and Species = = 
| Clinton | Niagara Helse. eae Choteau 
Inocaulis—con?’d. 
CLV ALiGAtUS=..05 cee eee eretoe late tenalcsy ane ah she H 
IMVOOMNCKIS cons cooovccooe> ocsochsceddaaa | SG 
HRT as osooonancveooons DCCC some dDd HSG 
(PROD MMENNOWES. se eonoscnscacsccsoopo0ceoas S 
TAMU LOSUS He eee a Pas aicnoutrcee hat eee Ayliaitas S 
W.AlKeriiey tse cae areTe atenteeie Sucav en le scare Reals SG 
hammnorrapiusmeeee wy crete ere | ? 
PHATtONeENSist ameter cree ciebe secures | SG 
WIENS sags adoo bods asus eoHoUooRDE COU D — 
FONIAC SUS PEMA RT etme celta, cae cisca nels SG 
CH CMO STATMG oo oocccocvvanccvogsgcobeDe cous = 
TOCAG SU UALUISE Pee cies ee eee Sl eee atte SG 
NOTES TO SUPRA-ORDOVICIAN TABLE. 
F signifies 7d@e A. F. Foerste. 
G signifies fde R. R. Gurley. 
H_ signifies 7de James Hall. 
HW signifies fde James Hall and R. P. Whitfield. 
R_ signifies fde E. N. S. Ringueberg. 
S_ signifies 7de J. W. Spencer. 
t] have examined a number of specimens of Spencer’s Phyllograptus dubius. It 
is found merely as a black stain on the dark brown weathered Clinton shales. In 
regard to it I am willing to say only that the specimens appear to be mostly, and 
probably are entirely, Diplograptids. At least two (perhaps three or even more) - 
species are present, as I found one which had the thecee about 1™™ apart, and 
another about 1.5™™. All the marginal fringing (which imparts somewhat the aspect 
of an Zzocaulis branch) is due to weathering. 
As regards the genus, there is little certainty, the specimens being very indistinct. 
Phyllograptus, of course, it cannot be and the present generic reference will probably 
prove to be the correct one. 
2See p. 79. 
3From Arctic America. 
4See p. 79. 
5 Only two authors have, I believe, touched on the possible presence of Graptolites 
in the Carboniferous. Portlock (Geol. Rep. Londonderry, etc., 1843, pp. 321, 322) 
says: “The family of Graptolites has at present no known representative in the Car- 
boniferous system; although a specimen from the mountain limestone, belonging to 
Captain Jones, M. P., has a strong resemblance to some of the double Graptolites.” 
And Hall (Pal. N. Y., 1859, III., p. 496) remarks that: 
