32 tl. F. MATTHEW: ILLUSTEATIONS OF 



peculiar iu the alatioii which extends along the axis of the stipe, without apparently 

 bearing cells at the margin ; it combines chara<'ters found iu Re/lolitrs (Barraude) aud others 

 of the immature stipes of some species of Dichograptus (Salter.) 



• Stipes thin, fiat, elongate, dicliotomously branched ; liaving a central axis, and being 

 alate on each side; pores arranged along the axis of the stipe; axis and margin of the 

 stipe connected by delicate nervures. 



Protograpsus alatus, u. sp. (Plate V. Fig. 6.) 



Koot, or initial point, xmknown. 



Frond dichotomously branching at wide angles, and usually angulated at a short 

 distance from the branches. The axis is subterete,and shows but little diminution in size 

 after branching : an alation or thin membrane, borders the axis on each side throughout ; 

 faint, thread-like ascending nerves diverge from the axis, at somewhat distant intervals, 

 and extend iu the direction of the defined margin of the lateral membrane. 



Cellules. Decorticated examples show the pores distributed along the axis at regular 

 intervals; iu some examples the pores are indicated by elliptical elevations along the axis, 

 but none have been observed which present the transverse ridges observable iu Deudro- 

 graptus (?) primordialis. 



Numerous fragments of this organism have been found, and it is readily recognized 

 by the alation of the stipe. In this respect it reminds one of the disc connecting the initial 

 branches of species of Telragruplux and Dirliograpl us (Salter) ; this alate condition, however, 

 appears to be a permanent one iu Protograpsus. Among the graptolites of the Quebec 

 group, G. crudfer, G- Headi and G. ahilux have the disk extended in the form of wings along 

 the sides of the stipe ; and in G. Logani (Geological Survey of Canada, Decade II, PI. IX. 

 Fig. 8) not only does the disk extend for some distance along the branches of the stipe, but 

 there is an appearance of a double row of cells along the lower branches, similar to the 

 minute nervures of the alation in Protograpsus. The nervures are arranged in a way similar 

 to those of RetMitex of Barrande (Geol. Surv. Can., Dec. II, PI. B. Figs. 20 and 21, and PI. 

 XIV. Figs. 3 and 4), but though there is a defined margin to the alation in Protograpsus, 

 no cellules have been detected on the margins of the membrane. 



Size. The length of the frond is unknown, but the width, including the alœ, is about 

 2 mm. 



Horizon aud Loralily. In the fine dark shales of Div. \.d, at Porter's Brook, St. 

 Martin's. 



III.— ECHINODERMATA. 



EOCYSTITES, Billings. 

 EOCYSTITES PRIM.i;VUSi, Billings. 



Acadian Greology, 2nd. Ed. p. 643, Fig. 220. United States Geological SurA'ey, Bulletin 

 10, p. 14, PI. I. Fig. 2. 



Various forms of cystidiau plates are found in the measures of Div. l.c, which serve 



