8 BULLETIN 65, UNITED STATES NATIONAL MUSEUM. 



Of this species I have only one speciuieii. It is '> cm. hig:h, besides the single 

 l)asal stipe, which is nearly 2 cm. long. The branches diverge from their initial 

 points on the stii)e until the summit is rather more than a centimeter broad, 

 although there are six or seven branchlets present, each having the breadth of a 

 millimeter and situated about the same distance apart. 



Formation and locality. — -This specimen was found in the Niagara dolomite at 

 the "Jolly-cut I'oad," Hamilton, Ontario. 



A single specimen from the Niagara dolomite, Hamilton, Ontario, 

 loaned by the Hamilton Museum (text fig. 8), agrees in all essential 

 points Avith Spencer's description, and apparently represents this 

 species. A drawing of this specimen was prepared by Doctor Gurley, 

 whose manuscript also contains the following notes upon the species: 



Evidently Spencer's figure represents a crushed or weathered specimen, so 

 that such deviations from it as occur here are merely such as would be expected 

 in better material. The branches mostly measure 0.8-1 mm. and are separated 

 by about their own width or a little more. The branches are more numerous 

 near the top, resulting in being more bushy in this region. This species is dis- 

 tinguished from the other siiecies at this horizon by the stoutness of its 

 branches and the size of the polypary. 



DENDROGRAPTUS FRONDOSUS Spencer. 



Text figure 7. 



Dendrograptus frnndosus Spencer, Can. Nat., X, 1SS2, p. 105, nomcn nudum; 

 Trans. Acad. Sci. St. Louis, IV, 1884, pp. 564, 568, 569, pi. 1, fig. 6; 

 Bull. Mus. Univ. State Missouri, I, 1884, pp. 14, 18, 19, pi. 1, fig 6.— 

 Miller, North Amer. Geol. and Pal., 1889, p. 184. — Gurley, Jouru. Geol. 

 IV, 1896, pp. 94, 308. 



Several fragmentary specimens from the Niagara dolomites, in 

 the collection of the U. S. National Museum, seem to belong to this 

 species. They show no features in addition to those pointed out in 

 the original description, which is as follows: 



The frond is low and broadly flabellate, originating from a short slender 

 stipe, which divides twice or thrice, after which the divisions extend to the 

 summit of the several lobes, and send off branches at irregular distances on 

 both sides. The branches give rise to lateral branchlets rather than bifurca- 

 tions. The branches are short and slender, not exceeding one-third of a milli- 

 meter in thickness. The surface is striated ; the cellular openings are minute 

 and oval, but usually indistinct. Figure (!(/ repi-esents an enlarged branch. 



This graceful little frond is less than 2 cm. broad, and li cm. high. 



Formation and localitii. — It occurs in the Niagara dolomite at Hamilton, 

 Ontario. 



DENDROGRAPTUS RAMOSUS Spencer. 

 Text figures :}. 9. Plate 1. figure 3. 



Dcndrograplufi ramoms Spencer. Can. Nat., X, 1882, p. 1G5, nomcn nudum; 

 Trans. Acad. Sci. St. Louis, IV, 1884, pp. 564. 567, pi. 1, fig. 3; Bull. Mus. 

 Univ. State Missouri, I, 1884, pp. 14. 17, pi. 1, fig. 3. — Miller, North 

 Amer. Geol. and Pal., 1889, p. 185.— Gurley, Journ. Geol., IV, 1896, 

 pp. 95, 308. 



