472 MISS G. L. ELLES ON THE GRAPTOLITE [^Ug. 1 898, 



The specimens now placed in this new variety were in 1894 pro- 

 visionally referred by Mr. Marr to Br. ramosus, Brogger/ A closer 

 examination has, however, convinced me that all the Skiddaw 

 Slate forms resembling Br. ramosus should be regarded as a distinct 

 variety of that species, and in this opinion Mr. Marr himself now 

 concurs. 



Occurrence. — The variety occurs in the Lower Skiddaw Slates 

 associated with Br. Kjeruljl, and I have seen one specimen on a slab 

 containing Tetragraptus Bigshyi (Hall). 



Locality. — Barf, near Keswick. 



Note on the Structure of Bryograptus. 



The examination of several specimens of Bryograptus in different 

 stages of growth, preserved in many ways and in various positions, 

 has convinced me that the stipes originate from the sicula in a 

 manner which is in all respects identical with that described for 

 Bidymograp t us. 



Fig. 5. — Stages in the development of Bryograptus 

 {coll. W. A. Brend). 



th2 

 Sicula 



[X5.] 



The ' initial bud ' in Br. ramosus var. cumbrensis, and I believe 

 also in Br. Kjerulfi, arises on the left side of the sicula at a point 

 about midway between apex and aperture. It then grows down 

 towards the aperture of the sicula, closely adpressed to it, and before 

 it diverges there is developed from it what seems to be the connecting- 

 canal ; this grows obliquely across the back of the sicula, and ulti- 

 mately gives rise to the first theca of the right primary stipe. The 

 phylogenetic value cf this will be discussed later. 



Genus Clonograptus, Hall. 



The branching in this genus differs from that of Dichograptus 

 and Loganograptus, in that the ultimate dichotomous division takes 

 place at a greater distance from the point of first dichotomy. 



1 Geol. Mag. 1894, p. 130. 



