1845.] BROCKEDON ON AN ARTIFICIAL GRAPHITE. 31 



pies of them have indeed occurred both in the oolitic and the palaeo- 

 zoic series, but I believe that these fossils have not hitherto been met 

 with in the lias. 



The Rev. P. B. Brodie, while pursuing his interesting and suc- 

 cessful researches into the fossil insects of the lower lias, was the 

 first to discover these minute objects. In a bed of yellowish shaly 

 stone, a few feet above the "insect limestone" of Wainlode Cliff, 

 Gloucestershire, he detected small white dots about g^th of an inch in 

 diameter, which when examined by a powerful microscope prove to 

 be discoid spiral shells, apparently unattached, with five or six smooth, 

 rounded, narrow volutions, devoid of striations or any other distinc- 

 tive characters. As there are no traces of concamerations, we per- 

 haps ought to refer them to the SerpulidcE rather than to the Fora- 

 minifera, although their extreme minuteness would point to the 

 latter family as a more probable clue to their affinities. It has been 

 suggested to me that their characters resemble those of the genus 

 Orbis of Lea, and I will therefore denominate the fossil provision- 

 ally Orhis wfimus (see figure (£). These fossils also occur in a si- 

 milar bed of shaly limestone near the base of the lias at Cleeve 

 Bank, between Evesham and Bidford. Along with them I here ob- 

 tained one specimen of an equally minute fossil, which exhibits more 

 decidedly the characters of the group Foraminifera^ and is refer- 

 able to the family Stichostega. It is an oval body, pointed at both 

 ends, smooth and glossy, convex, divided into three concamerations, 

 the largest of which extends all the length of the shell. As the 

 aperture is not visible, it cannot be referred with certainty to any 

 of the known genera of Foraminifera, but in general form it ap- 

 proaches sufficiently to the genus Polymorphina of M. d'Orbigny, 

 and we will therefore denominate it Polymorphina liassica (see 

 figure b). 



3. 0/j SpiRiFERs/ro/wMeLiAs. By James Buckman, Esq., F.G.S. 

 [Notice of this paper is postponed.] 



4. On a Method of forming the Dust of Grav rite into a solid Mass. 

 By W. Brockedon, Esq. 



The graphite, or black-lead of commerce, of sufficiently good quality 

 to be used for pencils, has become very scarce, only a small quantity 

 being now raised in the Borrodale mines, and that of inferior quality, 

 so that what has been sold lately is part of a large supply obtained 

 forty years ago. This quantity having been picked over and over 

 again, the former reputation of the Cumberland graphite is now 

 no longer sustained, and its impurity is detected by artists in conse- 

 quence of the grit which it often contains. 



The author of this paper has contrived a method by which the 

 fine dust of the best parts of the graphite may be recomposed into a 



