494- MIS^ G. L. ELLE3 ON THE GRAPTOLTTE [Auof. 1 898, 



(a) Phyllogra.pt US Anna, Hall. 



1865. Fliyllogra'ptus Anna, Hall, 'Grapt. of the Quebec Group,' Geol. Suvv. 

 Canada, dec. 2, p. 124 & pi. xvi, figs. 11-16. 



There are several specimens referable to this specie^?, both in 

 Mr, Postlethwaite's collection and in the Woodwardian Museum. 



It is characterized by its small size, and the great number of 

 thecse in a given unit of length. These number between thirty- 

 six and forty to the inch (fourteen to sixteen in 10 mm.). None 

 of the specimens are as much as ^ inch (12-7 mm.) in length ; 

 they appear to be commonly yV inch (10*5 mm.) long, and have a 

 maximum width of 4- inch (5*078 mm.), which is attained near the 

 distal extremity of the rhabdosoma. 



All the thecoe are curved, though the curvature is less in the 

 middle than at the proximal and distal 



extremities of the rhabdosoma. The Fig. 16. — Phyllograptus 

 thecse are in contact throughout their Anna (coll. Woocl- 

 length. wardian Mus.). 



One specimen in the Woodwardian 

 Museum seems to show in some detail 

 the structure of the proximal end. This 

 is on the same general plan as that indi- 

 cated by Holm for the species angusti- 

 folius. In this specimen one stipe has 

 been completely removed, and the sicula 

 and first theca are revealed. The sicula 

 is very long ; it measures ^2 ^^*^^ (^'-'^ r - nd 



mm.). The first theca, which appears to 



arise close to its apex, resembles the sicula rj^^t. size, and a portion 

 in form. magnified 10 diam.] 



A virgula is seen coming from the 

 apex of the sicula; it does not project beyond the distal extremity 

 of the rhabdosoma. So far as I am aware, no virgula has hitherto 

 been seen in the genus Phyllograptus. 



Occurrence. — With Phyllograptus angustifolius, Hall, in the 

 Middle Skiddaw Slates. 



Localities. — Eandal Crag, Skiddaw ; Barf; Carlside Edge. 



(e) Phyllograptus typus, Hall. 



1858. PJii/Uograptus typus, Hall, Geol. Surv. Canada Eep. 1857, p. 137. 



1865. Fliyllograptus typus. Hall, ' Grapt. of the Quebec Group,' Geol. Surv. 

 Canada, dec. 2, p. 119 & pi. xv, figs. 1-12. 



1868. Fliyllograpsm typus, Nich. Quart. Journ. Geol. Soc. vol. xxiv, p. 133 & 

 pi. v, fig. 16. 



Hall has well described this form as ' elongate-ovate, or lanceo- 

 late, broad oval or obovate.' The form is exceedingly variable, as 

 the following table of dimensions shows. The variation is largely 

 dependent on the amount of curvature of the thecse, which is very 

 different in different individuals : — 



