PLATE VIII. 

 Genus Trochograptus {coiifmneil) and Holograptus, Holm. 



FIGS. 



1 n, J). — Trocliorjraptns dijfusus, Holm. 



1 a. Large specimen, one fifth natural size. New Brow Quarry, 

 Upper Lorton. Middle Skiddaw Slates. Woodwardian 

 Museum. 



1 h. Diagrammatic sketch of portion of 1 a, natural size, showing 



method of branching. 



2 a — c. — Holograptus Deani, Lapw., MS. 



2 a. Very large specimen, one fifth natural size. Newlands, near 



Buttermere. Skiddaw Slates. Lapworth's Collection. 

 2 h. Part of branch, natural size, t^liowing tlie form of tlie tliecsB. 

 2 c. Part of 2 a, natural size, showino- method of brancliino". 



