DENDROID GRAPTOLITES OF HAMILTON, ONTARIO. 



same time giving off several slightly diverging brancblets at iri-egular distances 

 on both sides. The lower part of the stipe or trunk also gives off several branch- 

 lets. The outline of the frond is cleft or divided into somewhat rounded lobes, 

 with branches more or less upright. The corneous surface is strongly marked 

 with striations. The cellular openings are oval on one side of the axis, as repre- 

 sented in figure 5a. However, there are undulations or swellings on some of the 

 surfaces. 



This little fossil is one of the most beautiful of the Graptolite family found in 

 the Niagara formation. It is 4 cm. high and with a breadth of 2 cm., while the 

 branches are less than half a millimeter thick and nearly double that distance 

 apart. There is a strong resemblance to D. fruticosus of the Quebec group. 

 Only one good specimen is in my possession. 



Formation and locality. — This specimen was obtained by Colonel Grant in the 

 dolomitic shales, below the chert bed of the Niagara formation, at the " Jolly-cut 

 road," Ilauiilton, Ontario. 



No additional specimens of this species occur in the later collections. 



DENDROGRAPTUS DUBIUS Miller. 



Text figures 2, S. 



Dendrograptus simplex Spencer, Can. Nat., X, 1882, p. 165, nomen nudum; 



Trans. Acad. Sci. St. Louis, IV, 1884, pp. 564, 567, 568, pi. 1, fig. 4 ; Bull. 



Mus. L'niv. State Missouri, No. 1, 1884, pp. 14, 17, 18, pi. 1, fig. 4 (name 



preoccupied ) . 

 Dendrograptus diibins Miller, North Amer. Geol. and Pal., 1889, p. 184. — 



GuRLEY, Journ. Geol., IV, 1898, pp. 94. .308. 



8 9 



Figs. 8-9. — 8, Dendrograptus dubius Miller. An incomplete fkonu ; 9, Dendeo- 



GRAPTDS RAMCSUS SPENCgR. A FROND BRANCHING UNIFORMLY. (SeE ALSO PL. 1, FIG. 3.) 



Doctor Spencer originality described this .species nnder the name of 

 Dendrograptus sinipleu', a name preoccupied and replaced by Miller 

 with D. diihius. Tlie original description of D. simplex is as folloWs: 



Frond erect, with strong branches originating from a lengthy flexuous stipe, 

 and diverging slightly above. The branches bifurcate only once or twice and are 

 closely crowded together. Transverse bars are apparent in one or two places. 

 The texture is corneous, with surface striated. On one side there are oval de- 

 pressions marking the cell orifices; these are nearly a millimeter in length, and 

 are situated about double that distance apart. Eudimentary branches are given 

 off on each side of the stipe. 



82651— Bull. 65—09 2 



