﻿1850.] HARKNESS ON THE GRAPTOLITES OF DUMFRIESSHIRE. 03 



bably of considerable size. The thickness of the central canal ex- 

 ceeds the breadth of the cells, and these are directed outwards and 

 strongly recurved, their mouths distant ; the number of them in an 

 inch is about twenty, and they are well separated from each other. 

 The external covering appears to have been smooth, portions of shining 

 carbonaceous matter being found on its surface. It is of rare oc- 

 currence in the Duff Kinnell, associated with the G. Sedgwickii. It 

 is somewhat like the D. pristis of Portlock, with which it has been 

 compared, but that species has much closer cells, and they are not 

 recurved. 



2. D. nodosus, Harkness. 

 Pl. I. fig. 10. Natural size and magnified. 



In this species the polypidom is rectilinear and flattened, and is 

 but slightly attenuated towards the apex, the upper portion differing 

 but little from the lower. The axis occupying the middle of the 

 central column is well-developed and comparatively strong, and the 

 space separating the two series of cells appears in a great measure to 

 be filled up by it. The breadth of the central column is less than 

 that of the cells, which are directed outwards, and have the mouths 

 widely separated from each other. The base of the cells is broader 

 than the mouth, which is rounded, and a marginal depression occurs 

 just within the edge of the cells, perhaps due to the state of preserva- 

 tion. The number of cells in an inch is about sixteen, and the breadth 

 of the polypidom in the adult portion, including the cells, exceeds the 

 twelfth of an inch. 



This species is converted into iron pyrites, and the nature of the 

 external surface is not evident. It is rare, the only locality in which 

 I have found it being in the course of the Bran Burn, about thirteen 

 miles north of Dumfries. 



3. D. RECTANGULARIS, M'Coy. 



Pl. I. fig. 11. Natural size and magnified. 



(M'Coy, Catalogue of the Woodwardian Museum, pl. IB.) 



We have only fragments, though these are abundant, of a species 

 resembling in the outline of the cells the species above quoted. 

 Localities. Frenchland Burn, Moffat, and other places. 



4. D. folium, Hisinger, sp. 



Pl. I. fig. 12. Natural size and magnified. 



(Hisinger, Leth. Suec. tab. 35. Supp. fig. 8.) 



This pretty species, in the close approximation of the cells and 

 their general direction, is very like the species above quoted, but the 

 length of the individual cells is not so great, and our specimens are 

 consequently not so broad and obtuse as the Swedish species. Hi- 

 singer's figure does not show the close-set lines which traverse the 



