HISTORY OF RESEARCH. Iv 



at this date what might be called the British period of investigation began, 

 and for the next twenty years the great majority of papers thai appeared 

 emanated from British investigators — Salter, Carruthers, Nicholson, Hopkinson, 

 and Lapworth. 



18( . ( . Nicholson's first paper was devoted to the description of 



Nicholson, certain bodies occurring with Graptolites at Garple Linn, 



" Ovarian Vesicles or near Moffat, which he suggested might be " gonophores " or 



•Grapto-gonophores,'" "ovarian vesicles," and for which he proposed the name 



' Geol. Mag.,' vol. iii. ,, r* i " mi i v 1 i -i i • 



Grapto-gonophores. these bodies lie describes as being 



" corneous and bell-shaped," "provided at one extremity with a prominent spine 



or mncro, the other terminating in a gentle carved or nearly straight margin." 



Generally they are found free ; but in the case of Gr. Sedgivickii they occur in such 



close juxtaposition as to "justify the belief that the connection was organic, and 



not simply accidental." They appear to spring from the common canal or 



ccenosarc with the mncro at the free end. 



Nicholson points out that, if this interpretation he correct, the Graptolites must 



be " finally referred to the Hydrozoa, and would find their nearest analogues in 



the Sertularidge," "from which, however, they would always be separated by 



sufficiently distinctive and definite characters." 



1866 In H.M. Geological Survey Memoir on North Wales 



Salter, (published in 1860) Salter described and figured several forms 



Memoir Geol. Survey, of Graptolites. 



vo1 - iu - Of new species, he figures two — (1) Diplog. barbatulus 



(which it is at present impossible to identify), and (2) Dendrog. furcatula. Of 



species already named by previous observers, he refigures (3) Gr. Sagittarius (which 



he considers to be identical with Gr. virgulatus and Gr. Barrandei of Scharenberg, 



and which is probably a fragment of a Diehograptid) ; (4) Diplog. teretiusculus ; 



(5) ]J. mucronatus ; (6) l>. ramosus; (7) l>. bicornis (his two figures do not show the 



characteristic features of that species); (8) Didymog. geminus; ( ( .») D. hirando ; and 



(10) Dicttjonema sociale. The question of the structure and the affinities of this 



last mentioned form (which had first been figured by Salter in ' Siluria,' Edit. 2, 



1854) is entered into in much detail. Salter somewliat reluctantly accepts Hall's 



view of the identity of Eichwald's Gorgonia (flahelliformis), Angelin's Phyllograpsus, 



and his own Graptopora, with Hall's genus Victyonema. While lie considers the 



genus to have a "true relation with the Graptolite group," he regards it as a link 



connecting Graptolites with the Fenestellidse among the Bryozoa, under which 



class, indeed, following Huxley, he groups the Graptolites in general. 



Salter combats Hall's view that all the single-stiped forms of Graptolites are 



broken fragments of branched species, holding that the "evidence against it lies 



both in the mode of occurrence of these bodies and even more in the very complete 



scries of forms which can be furnished by our cabinets." " It is, moreover, certain 



