GRAPTOLITES OF NEW YORK, PART 2 



97 



graptus [see text fig. 38, 39] -.uul thereon mainly placed his claim of the closer 

 relationship between the graptolites and Rhabdopleura ; and then the 

 writer has been able to observe the presence of a continuous rod in the 

 vesicular swellings of the nemacaulus in Climacograptus and Glossograptus 

 [see tig. $^]. The inference of the presence in all the Axonophora (as 

 conceived by the present writer, i. e. with exclusion of the Dicranograp- 

 tidae) of this solid rod in the nemacaulus, is hence hardly to be doubted* 

 and in its presence would have to be seen a most important distinction 

 between the Axonolipa and Axonophora. 



SchepotiefFs sections show this remarkable rod which he terms the 

 "innere Stab der Virgula" to lie free in the center of the nemacaulus, one - - 

 inally held there by tissue not any more preserved. As it partly forms in 



m ffi ^ 



v- 





L 



--.3>S. 



39 



Fig. 38,39 M on ograp t u s priodon Eronn. Transverse [fig. 38] and longitudinal [fig. 39] sections show- 

 ing the nemacaulus (a S) with included virgula (i S). Copies from Schebotieff 



the wall of the sicula, it probably had also its origin in the wall of the nema- 

 caulus on the same side, we surmise, as in the sicula, and became only 

 secondarily free in the nemacaulus. 



The bearing of the presence of this supporting rod in the nemacaulus 

 on our conception of the mode of life of the Axonophora has already been 

 discussed by the writer in part i [p.517], and the purpose of this note is 

 merely to point to the fact of the recent verification of its actual existence 

 and to the inference of its general presence in the Axonophora. 



/"Sections of Climacograptus typicalis and Diplograptus amplexicaulis 



It has been observed in Climacograptus t y p ic a 1 i s [see descrip- 

 tion] and Diplograptus amplexi can lis [see descr.] that the cross- 



