^^2 MISS G. L. ELLES ON THE GEAPTOLITE [Aug. 1 898, 



Note. — The specimen from Barf is rather obscure, but, from the 

 number of thecae in the inch, it seems to belong to the above 

 species ; if so, it is a young form. 



(b) Glossograptus cf. Hincksii (Hopk.). 



1872. Diplograptus Sincksii, Hopk. Geol. Mag. vol. ix, p. 507 & pi. xii, fig. 9. 

 1876. Glossograptus Jffincksii, Lapw. Cat. West Scot. Foss. p. 7 & pi. ii, fig. 57, 

 & ' Grapt. of Co. Down,' Proc. Belfast Nat. Field Club, p. 134 & pi. vi, fig. 24. 



The specimen to which this description applies is not well 

 preserved, but it seems to resemble Gl Hincksii (Hopk.) more 

 closely than any other known form of Glossograptus. The specimen 

 is I inch (12-7 mm.) long, and near the proximal end the width is 

 y^ inch (1-58 mm.), exclusive of the spines; this, however, widens 

 gradually to a maximum of -^-^ inch (2-1 mm.). The character of 

 the proximal end recalls Cryptograptus antennarius (KdM) ; it is fur- 

 nished with a very short, stout, median spine, and two slightly curved 

 lateral spines about -^^ inch (2-1 mm.) in length. The spines are 

 very long and slender ; they have an average length of ^ inch 

 (3*2 mm.J ; they are probably complete on the right side of the 

 rhabdosoma. The distance between the spines gradually increases 

 towards the distal end, but is never greater than -^-^ inch (2-1 mm.) 

 in this specimen. 



The appearance on the right side suggests that every theca was 

 furnished with a spine, but I am inclined to think that this appear- 

 ance is misleading, and that the thecae are better seen on the left 

 side of the rhabdosoma at its distal end. Here their apertures are 

 visible, and they number thirty to the inch (twelve in 10 mm.) ; if 

 this be the true number, only every two or three can have had 

 spines. 



This form agrees with Glossograptus Hincksii : (1) in the gradual 

 increase in width ; (2) in the gradual increase in distance between 

 the spines ; (3) in the length of the spines. It has rather more 

 numerous thecae in a given unit of length, but this may be partly 

 the result of preservation. 



It differs (1) from Gl. ciliatus : (a) in the number of cells in a 

 given unit of length ; (b) in the character of 

 the base ; (c) in the length of the spines. 



(2) from Gl. armatus : (a) in general form ; (6) in the 



character of the spines. 



(3) from Gl. Jlmbriatus : {a) in the length of the spines ; 



(6) in the number of cells in a given unit of 



length. 

 Occurrence. — Ellergill Beds = Upper Skiddaw Slates. 

 Locality. — Thornship Beck. 



(a) Glossogeaptus aematus (Nich.). (Fig. 33, p. 523.) 



1869. Diplograjpsus armatus, Nich. Ann. Mag, Nat. Hist. ser. 4, vol. iv, p. 234 & 

 pi. xi, fig. 8. 



The specimens are all much distorted by cleavage, and show no 



