12 BULLETIN 65, UNITED STATES NATIONAL MUSEUM. 



inm. wide to the tips of the thecfe. It is probable that the latter are always situ- 

 ated on the side symmetrical with reference to the bisector of the angle included 

 between the branches, occurring on the side toward it. They are straight, 

 cylindrical, inclined about 25° to the branch, with the apertural margin straight 

 and perpendicular to the branch ; they are set about 45 in 25 mm. 



Horizon and locality. — This species is represented by a single speci- 

 men from the Niagara glaciated chert, at Hamilton, Ontario. 

 H olotype.— C?ii. No. 55295, U.S.N.M. 



DENDROGRAPTUS ONTARIOENSIS Bassler, new species. 

 Plate 1, figure 4. 



Although this form was distinguished by Doctor Gurley, who at- 

 tached the label ''^Dendrograptus ontariensis., type "' to the specimen 

 here figured, neither description nor figure could be found among his 

 manuscript pages. 



Dendrograptus onta7'ioensis is evidently closely re- 

 lated to D. praegracllts Spencer, from which, how- 

 ever, it ma}' be distinguished b}' its more regular, 

 erect growth, and by its dichotomously dividing, 

 rigid branches. Comparison of the figures of these 

 respective species will show other differences, but it 

 is believed that those mentioned will suffice for the 

 Fig. 12.— dexdko- recognition of this new form. 



GEAPTUS ONTA- ^ _ . . . - , 



EioENsis, N E w Horizou und locality. — This species is based upon 

 SPECIES. ^IEw single rather complete specimen in the collection 



OFTHEMOST *= ii 



COMPLETE sPEci- of tlic Chlcago Uuivcrsity, from the Niagaran dolo- 

 p^'i ^^fig'^T)' mites at Hamikon, Ontario. Several fragmentary 

 (By II. s. Bass- specimens in the collection of the U. S. National 

 ^'^^"' Museum agree with the type in all essential respects. 



Ilolotypc. — No. 1350(j, Walker Museum, University of Chicago. 



Genus CALLOGRAPTUS Hall. 



Callograptus Hall, Geol. Surv. Canada, Decade 2, 1SG5, p. 13.3; 20th Rep. 

 New York State Cab. Hist., ISGS, p. 218 (rev. ed., 1S68 [1870], p. 252).— 

 HoPKiNSON, Ann. and Mag. Nat. Hist. (4), X, 1872, p. 233. — Spencer, 

 Can. Nat., VIII, 1878, pp. 458-462.— z;ittel, Handbuch d. Pal., I, 1879, 

 p. 289.— Spencer, Can Nat, X, 1882, p. 165; Trans. Acad. Sci. St. 

 Louis, IV, 1884, pp. 562, 570; Bull. Mus. Univ. State Missouri, I, 1884, 

 p. 20.— Miller, North Amer. Geol. and Pal., 1889, p. 175.— Pocta, Syst. 

 Sil. Centre Boheme, VIII, Pt. 1, 1894, p. 179. — Matthew, Trans. New 

 York Acad. Sci., XIV, 1895, p. 271, pi. 48, fig. 5.— Gurley, Journ. Geol. 

 IV, 1896, pp. 93, 308.- Roemer and Frech, Leth. geog., I. Theil, Leth. 

 Pal., I, 3 Lief., 1897, p. 576. — Ruedemann, New York State Mus., Mem. 

 7, 1904, p. 583. 



Callograpsus Nicholson, Mon. Brit. Graptolitidte, 1872, p. 128. 



Gurlev's manuscript contains quotations from many of the papers 

 cited above, but no original notes are included. The following quo- 



