516 MISS G. L. ELLES ON" THE GRAPTOLITE [Aug. 1 898, 



a distinctly higher horizon ; this is also borne out by the fauna, 

 which is essentially of the uppermost Arenig type. Though I did 

 not obtain Az. suecicus from this locality, the graptolites that I did 

 collect are all those with which it is commonly associated at Barf. 



Az. coelebs is found at EUergill with a still higher type of fauna, 

 whose characteristic fossils are species of Diplograptus and Climaco- 

 graptus, none of which have been recognized at lower horizons. 



Genus Leptograptus, Lapw. 

 Leptograpttjs sp. 



There are in Mr. Postlethwaite's collection, and in the British 

 Museum (IS'at. Hist.), a few fragments of stipes of a species of 

 Leptograptus which seem in every case to be the same. 



The genus is easily recognized by the peculiar form of the thecse. 

 In one specimen a portion of both stipes is seen, but unfortunately 

 no details regarding the thecae can be made out. 



The stipes are flexuous and very slender ; they have a width at 

 their origin of -^-^ inch ('42 mm.), but widen to a maximum of 

 -^ inch ('63 mm.). 



The thecEe show the characteristic Leptograptus-ioim. ; they number 

 twenty-four to the inch (nine to ten in 10 mm.), rather more near 

 the proximal end ; are inclined at a low angle of 15° to 20°, and 

 are in contact with each other for about half their length. 



Occurrence. — Uppermost Skiddaw Slates. 



Localities. — Aik Beck, Pooley ; Bassenthwaite Sand-beds. 



Genus Dicellograptus, Hopk. 



DlCELLOGRAPTTJS MOFEATENSIS (Can.). 



1858. Didymogra'psus moffatensis, Carruthers, Proc. Roy. Phys. Soc. Edinb. vol. i, 

 p. 469 [fig. 3]. ' 



1859. GraptoUthus divaricattis. Hall, Pal. N. Y. vol. iii, Suppl. p. 513, figs. 1-4. 

 1865. Dicranograptus divaricatus, Hall, ' Grapt. of the Quebec Group,' Geol. Surv. 



Canada, dec. 2, p. 57. 



1870. Didymngrapsus divaricatus, Nicb. Ann. Mag. Nat. Hist. ser. 4, vol. v, 

 p. 350 & pi. vii, fig. 4. 



1871. Dicellograptus moffatensis, Hopk. Geol. Mag. vol. viii, p. 25 & pi. i, fig. 4. 



1875. Dicellograptiis moffatensis, Hopk. & Lapw. Quart. Journ. Geol. Soc. 

 vol. xxxi, p. 654, pi. xxxiv, tigs. 3 a & 6 & pi. xxxv, figs. 5 a & 6. 



1876. Dicellograptus moffatensis, Lapw. Catal. West Scot. Foss. pi. iv, fig. 84. 



The actual characters of the cells are difficult to make out, but 

 they number about twenty-four to the inch (nine to ten in 10 mm.), 

 and the form of the species leaves no doubt as to its identit}'. In 

 one specimen the presence of a membrane is indicated by a band 

 passing across between the dorsal walls of the stipes, rather above 

 the level of the aperture of the second theca. 



Occurrence. — Upper Skiddaw Slates. 



Localities. — Only two specimens are known to me; one occurs 

 on a slab with Diplograptus pristiniformis from the Upper Skiddaw 

 Slates of Thornship Beck, and the other from Mosedale Beck, near 

 Troutbeck. Others have, however, been recorded from Barf; Bandal 

 Crag, Skiddaw ; and Bassenthwaite Sand-beds. 



