(lUAPTOLITES OV XKNV YOUK, PART 1 ()41 



wider .-lugle of divergence of the branches, in the somewhat closer arrangement 

 and smaller angle of inclination of the thecae ; in all other characters it agrees 

 closely with that form. The British species occurs in a lower horizon than 

 E . 1 a p \v o r t h i . 



Bryograptus pusillus sp. nov. 



Plate i. Hgures 21, 22 



B ry ogr a p t ITS kjeriilfi (Lapworth) RnedemaiiB. N. Y. State Paleontol. An. 

 Rep't. 1902. p.556 



This species is represented hy a single, well ]n'eserved specimen fonnd on 

 a slab from grai^tolite bed 2 (Tetragraptus bed). 



Description. Rhabdosome small (6 mm long excluding the nema) 

 consisting of a compact group of de]5endent branches. It begins with a 

 long, delicate nema, to wliicli a large relatively broad sicula (1 mm long) 

 is attached. From this originate two primai'\' branches at an angle of 

 about 50", each of which bifurcates into two secondary branches. The 

 innermost of these divide again below the next theca. The earlier bifurca- 

 tions take place symmetrically. The thecae which are disposed along the 

 inner margins of the branches are long and narrow, four times as long as 

 wide, slightly curved; they number 10 in 10mm; overlap apparently not 

 more than one fourth of their length, and form an angle of about 15° with 

 the axis of the branch. The aperture is slightly concave ; the apertural 

 angle has not been accurately determined, but is larger than 90°. 



Position and localities. A single specimen has been found on a slab of 

 graptolite bed 2 ^vith Tetragraptus c a d u c e u s . 



Remarlcs. This form in its habit and specially in its mode of branch- 

 ing is a diminutive example of B . k j e r u 1 f i . I had, for this reason, 

 originally referred it to that species, considering it a belated mutation of 

 the same [1902, p.556 j. The elaborate descriptions by Miss Elles and 

 the exact drawings by Miss Wood, however, which have meanwhile 

 appeared in the Monograph of the British Graptoiites, allow^ a more con- 

 olasive comparison of our excellentlx' ]ireserved specimen with the European 

 material of B . k j e r u 1 f 1 . By this we find that it differs from the latter 



