DENDROID GRAPTOLITES OF HAMILTON, ONTARIO. 



37 



This species has the branches slightly thicker and somewhat more nnnier- 

 ons than In D. rctiforme, which it most resembles. It is therefore a closer form 

 than retiforme, the interspaces nsnally tending to be narrower, or at least not 

 wider than the branches, especially distally, where, on the contrary, in D. 

 retiforme, the tendency is for the interspaces to be, relatively to the branches, 



Fig. 46. — Dictyonema spexceui, new species. Holotype. (See also Pl. 4, fiu. 1.) 



widest, this condition resnlting from a tendency of its branches to spread too 

 rapidly for bifnrcjition to keep pace with the spreading. This of conrse shows 

 in the number of branches in 25 mm. of width, which at the periphery of D. 

 retiforme tends to sink to say 15. 



UoIofi/pc.—CAt. No. 55301, U.S.M.A. 



DICTYONEMA PARALLELUM Gurley, new species. 



Plate 4, figure 2. 



The description by Gurley is as follows: 



Polypary originating from a fibrous root; consisting of 

 rigid, wiry, parallel, little-diverging branches, mostly 0.4 

 mm. wide, but reaching 0.6 mm. in the proximal portion ; 

 set 35^0 transversely in 25 mm. Meshes correspondingly 

 narrow, being usually about one-half as wide (but, from 

 slight curving of the branches, may for short distances be 

 as wide) as the branches. Bifurcations not numerous. 



Branches connected laterally both by slender, transverse 

 dissepiments, and in places by transverse bands of epi- 

 dermis; the latter about as wide as the branches. Judg- 

 ing from the few seen, the dissepiments are about 2.5 mm. 

 apart, but this may easily be erroneous, as intermediate ones may have been 

 destroyed. The epidermis over the branches is in several places crossed by 

 transverse lines which probably mark the position of thecfe. These lines are 

 approximately half a millimeter apart (corresponding to about 50 theciB 

 in 25 mm.). 



This species is easily recognizable by the rigid, wiry branches, very thickly 

 set, with correspondingly narrow (nearly obliterated) meshes. 



Fig. 4 7. — Dictyo- 

 nema PARALLELUM, 

 new species. 

 Holotype. (See 



ALSO Pl. 4, FIG. 2.) 



