474 MISS G. L. ELLES ON THE GEAPTOLITE [Aug. 1 898, 



of every order. They number about twenty-five to the inch (ten 

 in 10 mm.). They are narrow tubes, with slightly curved walls, 

 and are four times as long as wide ; they are inclined at an angle of 

 about 30°, and are in contact for half their length. These apertures 

 are straight, and are perpendicular to the general direction of the 

 stipe. 



In no specimen have I observed a disc. 



L c a 1 i t y . — Unknown . 



(6) Clonogeaptus cf. TE]!fELLTJs (Linnarssou). 



1871. DicTiograjptus (?) tenellus, Linnarsson, Ofv. Kongl. Vet. Ak. Forh. Stock- 

 holm, vol. xxviii, no. 6, p. 795. 



1876. Dichograptus tenellus, Linnarsson, Geol. Mag, dec. 2, vol. iii, p. 242. 



1892. Clonograptus tenellus, Moberg, Geol. Foren. Stockholm Forhandl. vol. xiv, 

 p. 89 & pi. ii, tigs. 1-3. 



A slab on which are two specimens of a species closely resembling 

 Linnarsson's CI. tenellus is in Mr. Postlethwaite's collection ; it was 

 shown to Prof. Lapworth some years ago, and he then said that 

 it seemed to him to be identical with a form occurring in the 

 Tremadoc Beds of North Wales. 



The best specimen is by no means perfect, but it is well pre- 

 served ; it shows the two stipes of the 1st order, and three out 

 of the four stipes which arise from these by dichotomous division. 

 The other stipe is embedded, and only two out of the three are seen 

 to divide further. Stipes of 5 orders are visible within a length 

 of 1^ inch (31*7 mm.). The angle between the stipes of order 2 

 is 90°, between those of order 3, 75°, those of order 4, 60°, and those 

 of order 5, 50°. The branches become longer as they reach a higher 

 order : in other words, the distance between the points of dichotomy 

 increases with remoteness from the base. 



The species is very slender ; it never exceeds -^ inch ('5 mm.) in 

 width, including the thecse. The stipes are very slightly flexuous. 

 The thecse number twenty to the inch (five in 10 mm.) ; they are 

 inclined at a very low angle, and are in contact for a very short 

 distance at their base ; their outer wall is straight or very slightly 

 curved. The apertures are concave, submucron ate, and very slightly 

 oblique to the general direction of the stipe. The species is cha- 

 racterized by its extreme tenuity. 



Locality & Horizon. — Barf. Lower Skiddaw Slates. 



(c) Clonogeaptus sp. 



On many slabs of the Skiddaw Slates I have observed several 

 dichotomously-divided stipes of what I believe to be a species of 

 Clonograptus^ though in their fragmentary condition specific deter- 

 mination is not possible. Por the most part, they appear to be the 

 ultimate stipes ; they are slender, flexuous, and rather delicate, 

 having a maximum width of not more than -^^ inch (1*05 mm.). 



The thecae are very clearly seen ; they are long narrow tubes, 

 of uniform width, numbering twenty to the inch (eight in 10 mm.). 

 They are in contact for two-thirds of their length, and have straight 

 apertures, which are situated perpendicularly to the general direction 

 of the stipe. 



