52 



BULLETIN 65, UNITED STATES NATIONAL MUSEUM. 



long), each ending in ilicliotonious froe points. Texture corneous, with a sur- 

 face apparently composed of scaly fibers. 



Of this species the fossils are not very well preserveil. There is some indica- 

 tion of a central axis. This species is e.isily distinguished from /. plumulosus 

 by the close, regularly arranged, parallel branches from each side of the princi- 

 \y,\] stipes and by their terminal branches. The fronds appear to have grown 

 in groups, but whether they are connected at the base or not is unknown. If not 

 connected, the individual fronds (in the specimens under consideration) are 

 about 4 cm. high and 3 broad, with from 3 to 5 principal branches on either 

 side of the central stipe ( the branches are more numerous on one side than the 

 other). The character of the cellules is unknown. 



Formation and localiti/. — Inocaiilis i)hucoi(1cs occurs in the dolomitic lime- 

 stones of the Niagara formation at the " Jolly-cut " quarries, Hamilton, Ontario. 



A specimen doubtfully referred to this species occurs in the Na- 

 tional Museum collections. l)ut shoAvs nothins: in addition to the above. 



INOCAULIS DIFFUSUS Spencer. 



Inocaulis diffufia Spencer, Canadian Nat., X, 1SS2, p. 165, nomen nudum. 



Inocaulis diffusus Spencer, Trans. Acad. Sci. St. Louis, IV, 1884, pp. 565, 

 586, 587, pi. 5, fig. 4 ; Bull. Mus. Univ. State Missouri, I, 1884, pp. 15, 

 36, 37, pi. 5, fig. 4.— GuRLEY, Joum. Geol., I^', 1896, pp. 99, 308. 



This species was described by Spencer as follows : 



Frond originating in a single stiiie at base, and rising above in numerous 

 widely extended branches averaging about a millimeter in breadth, with dicho- 



tomous terminations ; branchlets origi- 

 nating more frequently on one side 

 than on the other. Texture corneous, 

 with surface more or less i-egularly 

 striated, leaving in some places small 

 oval impressions (pi'obably the ori- 

 fices of the cellules). 



Of this species I have seen only 

 one good specimen (and two inferior 

 fragments which jn-obably belong 

 here). The frond is 6 cm. high and 

 of still greater breadth. One of the 

 branchlets of the dichotomous termi- 

 nation is much more slender than 

 the other (a sort of lateral pustule), 

 indicating probably the commencement 

 of the growth of a new branch. 



The general form of this species 

 is like /. Ullus (Hall and Whitfield), 

 but it is much larger in size, having 

 more diffused branches, with an en- 

 tire absence of prong-like processes 

 from its sides. 



FoDiiatioii and locality. — The type 

 of this species was obtained by Colonel Grant, near the base of the " cherty 

 bed " at the " Jolly-cut," Hamilton, Ontario, in the Niagara dolomite. 



Fig. 



67. — Inocal'lis dcffusus Spencer. 

 Copy of Si-enceh's figure. 



