72 W. Carrutliers — On the British GraptoliteSy 



generic value, retaining for the first the original name, and pro- 

 posing Diplograpsus for the second. 



Barrande, accepting Hisinger's determination, considered the 

 Friodon Sagittarius of that author the same as G. Sagittarius, Linn., 

 and so held the species with a single series of cells to be the true 

 Linnfean type of the original genus. He further endeavoured to 

 show that Cr. scalaris, Linn., was a " scalariform " impression of a 

 single-celled species, and, by an oversight which is remarkable in a 

 work specially characterised by the careful and accurate observation 

 that distinguishes all the labours of its illustrious author, he figures 

 a double-celled Graptolite as the '' scalariform " impression of two 

 single-celled species, viz. G. nuntius, Barr., and G. Kalli, Barr., as 

 has been already pointed out by Hall. M'Coy, following Barrande 

 and Hisinger, retained erroneously, as I have shown, the Linnasan 

 name for the single-celled forms. Were it not that he has been 

 invariably followed, I would have restored the name given by 

 Linngeus to the only form with which he was acquainted ; but this 

 would introduce into the accepted nomenclature so many changes 

 without corresponding advantages, that the strict application here of 

 the law of priority would scarcely be justifiable. To correct to 

 some extent the error, and to make the extent of the acquaintance 

 which Linnaeus had with these fossils more obvious, I have substi- 

 tuted for G. Sagittarius, Linn, (a name which cannot be maintained), 

 that of G. Kisingeri, after the distinguished palaeontologist who first 

 described the species, but erroneously ascribed to it the Linnaean name. 



Suess, in 1851, added the name Petalolithus as a synonym to 

 M'Coy's genus Diplograpsus. In the same year M'Coy gave the 

 name of Bidymograpsus to a well-marked group, and in the following 

 year Geinitz applied Cladograpsus to the same group. Unaware 

 that this name had been employed, I proposed it in 1858 for a 

 repeatedly branching form which I found at Moffat. While the 

 paper in which I described this and other forms was passing 

 through the press, I learned that Geinitz had used the name : but as 

 I was unable to ascertain to what group he applied it, I permitted 

 the name to stand, in the faint hope that we had independently 

 selected it for the same form. In the same paper I described a new 

 species of Didymograpsus, and recorded two other already described 

 species, so that it is perfectly obvious that I applied the name to a 

 different group from that which Geinitz had included under it. 

 In 1867 Dr. Nicholson gave Pleurograpsus to be placed as a synonym 

 to my genus Cladograpsus. 



Salter, in 1861, described a compound form Dichograpsus from the 

 Skiddaw slates, similar to some that had already been observed in 

 Canada by Sir Wm. Logan. 



Hall has more than any other palagontologist increased our ac- 

 quaintance with species of graptolites, and added many very re- 

 markable genera. His extensive acquaintance with the perfect and 

 singular specimens that have been found in Canada and the United 

 States have given him a high vantage-ground, which, independent of 

 the care and ability with which he prosecutes his investigations, would 



