NORTH AMERICAN GRAPTOLITES 307 
22“Tfudson River Group of lowa” (Hall). 
23Cf. D. foliaceus calcaratus, Lapw. (in Armstrong, Young & Robertson’s Cat. 
West Scottish Foss., p. 6, Pl. IL, Fig. 30.) The latter is a Hartfell species. The iden- 
tity of the two forms can hardly be asserted at present as Lapworth’s calcaratuts, rests 
solely upon the figure of a basal fragment. Still, had I had access to his figure, I should 
not have described LD. ¢rifidus. 
*4 Entirely overlooked by cataloguers. Horizon, from label on type in American 
Museum of Natural History, New York City. Locality, Turin, Lewis county, N. Y. 
25’Trenton Limestone of Wisconsin. 
76] suspect that, as Prof. Whitfield (Mem, Amer. Mus. Nat. Hist., N. Y., 1895, 
I., pp. 40-41) believes, this genus is non-graptolitic. 
77 One species from the Trenton of Minnesota; three species from the Cincinnati 
group at Cincinnati, Ohio ; all in the collection of Mr. Ulrich. 
28 “ Tower beds, Cincinnati Group ” (Ulrich; label). 
29 Diplograpsis ruedemanni Gurley, sp. nov. 
(Diplograptus pristiniformis, Ruedemann, 1895, Amer. Jour. Sci., pp. 453- 
455, Figs. 2, 3; Diplograpsis ruedemanni Gurley, nom. nud., supra, p. 78). 
Entire polypary consisting of a number of diprionidian stems (“ polyparies”’ as 
formerly understood) originating in and radiating from a common central “disk” 
(Ruedemann). Diprionidian stems quite small, the greatest length observed (in 
incomplete specimens) 7™™. Maximum breadth 1.5™™ (a single stout specimen 
reached 1.75™™"). Thecze cylindrical, the breadth practically the same throughout and 
their axis practically straight; 38-50 in 25™™ as nearly as determinable (ranging 
from 2 in 1™™, 7 in 4™™, 5 in 3™™, to 3 in 2™™). Aperture in scalariform impression, 
squarish, 0.6-0.8™™ on a side; margin straight, in the large majority of specimens 
appearing perpendicular to virgula, thus producing a deep indentation, a shorter 
overlap (§-%), and an acute “denticle.” But I believe (the material not perfectly satis- 
factory) that the real condition is: margin inclined to virgula on proximal (“distal”) 
side about 60° (say 55°-65°), and an overlap of %. Inclination of the thecz on 
proximal (“distal”) side to virgula, 40°. 
I know but six Diplograpses with as many thece in 25™™, viz.: D. status Nich., 
and LD. zxsectiformis Nich., both Upper Silurian species; D. confertus Nich., whose 
breadth (8™™) alone suffices to exclude it: D. pzztzdlus (Hall), which has 34-38 thecz 
in 25™™ without overlap; 2. mzzzmus Carr., with which the present species will bear 
comparison ; and LD. hudsonicus Nich. From the last D. ruedemanni differs in the 
form and amount of overlap of the thecze and in lacking the spine on the lower lip of 
the aperture. é 
Horizon and locality.—Utica Shale, near Dolgeville, N. Y., dedicated to the dis- 
coverer, Dr. R. Ruedemann, of Dolgeville. 
3° Fide Whitfield (Rep. Wheeler Surv., 1875, IV., p. 19). I do not believe these 
genera occur in the Utica, and think with Lapworth, that the Didymograpsus was 
probably a Zeffograptus. As in Britain the Glenkiln, so in America its equivalent, the 
Lower Dicellograpsus Zone, seems to mark the last appearance of the genus Dzdymo- 
Lrapsus. 
