

50 BULLETIN 65, UNITED STATES NATIONAL MUSEUM. 



branches averaging 2 mm. in breadth for the larger and 1 mm. for the smallei; 

 toward the margin of the frond, where the branchlets end in two (sometimes 

 three) extensions of unequal thickness. Texture corneous, with the surface 

 composed of scaly fibers. Extending longitudinally through the stipes are 

 central or subcentral elevations (sometimes depressions), indicating a solid 

 central axis. 



This species is described on two specimens, one of which shows the origin 

 and base of the radiating branches, and the other the general frond, although 

 the radicle is concealed. The extreme width of the typical specimen is 14 



cm., and the height 8 cm. 



In general form this spe- 

 cies differs from /. plumulo- 

 sus in that the branches are 



^WIHJHIVfK^M #/ll#S9V nVK# more slender and rise regu- 



^"^^-VmIt Jllii^A#/jRr3&.Mt^i larly and more abundantly 



^.^ , ,__ __ —I,— .—, from the sides of the main 



V^vi/\^(^^jP^Pj]^ J ^lBK^^^^Mt Ktiiies, which radiate trom a 



common origin and do not 

 consist of groups of individ- 

 ual fronds. The radicle ap- 

 pears to have been attached 

 to some rocky surface iu 

 the sea, and not to have 

 grown on some muddy bot- 

 tom. The cell-bearing stipes 

 appear to have had a com- 

 mon canal, through the cen- 

 ter of which was a central 

 solid axis, as is also indi- 

 cated in 7. cervicornis. 

 FIG. 64.-INOCAULI.S li^^MULuscs SPENCER. SPECIMEN formation (uid localify.- 

 IN U. S. National Museum. 



These specimens were ob- 

 tained in the shaly dolomites, below the " chert beds" of the Niagara formation 

 at the " Jolly-cut," Hamilton, Ontario. 



Doctor Gurley's notes are as follows : 



Polypary, in the single specimen seen, rising from a stem which gives off, in 

 the proximal half of the portion visible, vei'y few branches which, moreover, 

 do not rebranch into a bushlike form, the bushlike branching occurring only 

 in the distal half of the polypary. The only proximal branch distinctly seen 

 bears a close spike of straplike, processes (abortive branchletsV). Distally the 

 polypary branches out bushlike, the main branches about 1 mm. thick. At or 

 near the summit the branches subdivide into 2 or 3, usually unecpial or sub- 

 equal, terminal twiglets. The sides of the branches are usually slightly fringed; 

 the processes hairlike, few and remote. 



The stems of this species remotely resemble those of Acdiitliof/idiihif; finnitl, but 

 they are nmch more remotely and much more linely fringed, and in its ensemble 

 this si)ecies has the branches less rigid and parallel than has .1. gninti. 



Jlorhoh and locality. — Xiagaran (Lockport), Hamilton, Ontario. 

 Plesiotype.—Cvii. No. 55314, U.S.N.M. 



