164 Mr. C. Lap worth on new British Graptolites. 



tinct. Hall's second figure belongs clearly to a different 

 species — one representative, it may be, of Dicellograptus patu- 

 losus. 



Family Dichograptidae. 

 Bryograptus, gen. nov. 



Polypary bilaterally subsymmetrical, consisting of two 

 compound monoprionidian branches diverging at a small 

 angle from a well-marked sicula, and originating similar 

 compound (or simple ?) secondary branches at close but irre- 

 gular intervals from one margin only. Hydrothecae minute, 

 of the type of those of Dichograptus, Salt. 



This genus differs from Dichograptus and Clonograptus 

 mainly in the fact that the secondary and tertiary branches 

 are given off at irregular intervals, while the two chief 

 branches, instead of proceeding outwards in opposite directions, 

 make but a small angle with each other, composing an irre- 

 gular polypary of an irregular dendroid form. It is doubtful 

 if this latter feature is of any great systematic importance, as 

 both Didymograpti and Tetragrapti of slightly divergent type 

 are known. Nevertheless the habit of the two Cambrian 

 species here united under this title is so distinctive that they 

 may well be provisionally separated from Dichograptus until 

 they are more perfectly known. Only two forms have yet 

 been met with. The first is figured in Kjerulf's ' Veiviser,' 

 published at Christiania in 1865. The second was collected 

 by Dr. Callaway in the Shineton Shales of Shropshire in 

 1873. They are here noticed because of their geological 

 importance, being the oldest forms of Graptolithus hitherto 

 detected. 



19. Bryograptus Kjerulfi, sp. nov. 

 (PI. V. figs. 22 a, 22 b.) 



Graptolithus tenuis, Portlock, Kjerulf, Veiviser, p. 3, figs. 6, a, b, 

 A,B. 



Polypary consisting of two very slender primary branches 

 diverging from a well-marked sicula at an angle of about 

 40°, and giving origin to two (or more) compound secon- 

 dary branches at close intervals from their inner margin. 

 Hydrothecse eighteen to twenty-four to the inch. 



The above description is drawn up from Kjerulf's figures 

 (a and b). If the figures can be depended upon, the habit of 

 the species is so unique that there can be no doubt of its 

 distinctness from any species of the Dichograptidae hitherto 



