GRAPTOLITES OF NEW YORK. PART 1 487 



be properly transferred to them. The funicle is, then, the common base of the 

 nemacauluses of the rhabdosomes or persons of the second order in the Axon- 

 ophora, or one of the central parts of the person of the third order, while the 

 " funicle " of the Diehograptidae represented but the central part of a person 

 of the second order. 



The sicula is suspended by means of a flexuous, filiform process which has 

 been termed the nema or linea by Lapworth [1897, p.251], and hydrocaulus 

 by the writer [1895, p.224j. In the last cited paper it has been shown that 

 the proximal prolongation of the axis of the rhabdosome of Diplograptus 

 known as virgula is identical with this nema or hydrocaulus. This latter is 

 a hollow process, capable of further growth. There originates however in the 

 wall of the sicula of the Axonophora, as AViman has demonstrated, a solid 

 rod, to which the latter author has applied the name mrgula. This rod is 

 not present in the sicula of the Axonolipa, and, as the writer's observation 

 would indicate [1897, pl.2, fig.6], it extends into the nema of the Axonophora. 



A sharp distinction between the hollow proximal prolongation of the 

 sicula, present in all Grraptoloidea, and the solid axis, originating in the wall 

 of the sicula of the Axonophora and probably extending into the first named 

 prolongation, hence becomes necessary. For this reason, the writer had 

 proposed to name the hollow process hydrocaulus and the solid axis the 

 virgula. As the term hydrocaulus is however taken from the Hydroidea, 

 where it represents an analogous process, connecting the first receptacle of the 

 embryo and the disk of attachment [see ch.7, p.523], it appears practical to 

 discard it for one of the neutral terms, nema or nemacauluSj proposed by 

 Lapworth. The term nema would well express the fiej^uous character of this 

 organ in the Axonolipa, and the term nemacaulus the more rigid character in 

 the Axonophora. 



In certain Diehograptidae the bases of the stipes are " united by a 

 thickened corneous expansion " which was termed by Hall the central dish. 

 The writer has observed a chitinous disk in the early stages of various forms 

 [see ch.7, p.535], from which the sicula is suspended. This w^e call here the 

 primary disJc^ as it is clearly a more or less essential part of the first growth 



