96 G. F. MATTHEW ON THE 



branches are about one-half of a millimetre wide. The cells of the hydrosoma are directed 

 forward and each terminates in a mucronate point. The branches are a little more than 

 half a millimetre wide. The primary branches do not appear to be celluliferous, but ccll- 

 beariug branches shoot out from the primary. 



Horizon and Locality. In the black carbonaceous slates of Division 36 at Navy Island 

 in St. John harbour, in company with Dictyonema flabeUiforme, Eich. 



This species exhibits a tendency to develop cross-bars on some of the branches. 

 They are not incipient ascending branches, but short processes, directly transverse to the 

 branch ; they do not appear to be of the nature of the transverse connecting threads which 

 one sees in a Dictyonema, but are short stout outgrowths of the branch, and are usually 

 directly opposite each other. 



This species is distinguished from Diclyonema flabeUiforme, whose fragments occur 

 with it, by the thinness of the substance of the hydrosoma which thence shows a less 

 brilliant reflection from the surface of the shale than the above named species. 



I at first thought this species might be B. Kjerulfi, Lap., figured by Dr. Brogger, ^ but 

 that species has a less spreading habit of growth, and the mouths of the cells are different 

 in form. B. Kjeridfi occurs in the Norwegian Cambrian layers 2e, our species is found 

 with a trilobite fauna similar to that which occurs in their layers 2c, consequently it is 

 homotaxically older. 



DICTYONEMA, Hall. 



Dictyonema delicatulum, Dawson, var. 



Eep. Peter Redpath Museum of McGill University, 1883, p. 16. 



Examples of a Dictyonema allied to this species are found in the graptolite beds at the 

 Suspension Bridge. The mesh is not quite so fine as that reported for the above species : 

 that has 18 branches in the space of a centimetre, this has 14 or 15 ; in that the transverse 

 bars are said to be more distant than the vertical stems, in this they are less so, there being 

 about 13 bars in the space of a centimetre. The cells are poorly preserved, but appear to 

 be alternate, and distant, giving to the branch a flexuous appearance ; in D. delicatulum they 

 are said to be in one series, round in cross section, and have a pointed aperture. As in the 

 species named our form is elongate funnel-shaped Examples 6 cm. long and 1| cm. wide 

 of D. delicatulum from Quebec, correspond in form to the species above mentioned, from the 

 St. John group. 



Horizon and Locality. From black slates of Div. M at the Suspension Bridge. 



Dictyonema quadrangulare, Hall. 



Can. Org. Rem. Dec. ii., p. 138, PI. xx., fig. 5. 



This species is represented by a few examples. 

 Horizon and Locality. Same as the preceding. 



Die SilurischenEtagen 2 iind 3. PI. 12, figs. 20 and 20(i. 



