No. 373-] THE STUDY OF GRAPTOLITES. II 
which is shown in section 26, while in section 28 the opening 
of the next gonangium can be seen. 
The hayfork-like outgrowths of the thecæ observed by Holm 
and Wiman are supposed by the latter to have aided in the 
process of propagation. In the writer’s opinion, they also 
remind one of the nematocalyces of certain Plumularidz, which 
are similar processes provided with a nematophore or altered 
individual for the purpose of seizing food. They would then 
constitute a fourth kind of individual. 
While it becomes apparent from these discoveries that the 
three groups of graptolites are more different than had been 
21 22 23 
pee 
2 
P 4 
© 
fk, % KN ” 
& 
3, 
t $ 
K ' 
25 26 27 "© 28 
FIGS. 21-28. — Dictyonema rarum Wiman: series of transverse sections (Wiman). 
supposed, it yet seems allowable to retain them in one class. 
The systematic position of this class seems, by the observed 
complex structure of the periderm and the high organization of 
- the rhabdosome in general, to have become more uncertain than 
ever before. As we saw before, the grapolites have, for a long 
time, quite generally been united with the campanularians. 
Lately, objections against this union have been raised, espe- 
cially by Jækel and Neumayr (‘g9). Wiman holds the same 
view as Neumayr, namely, that the graptolites cannot be placed 
in any of the groups of living animals, while Ruedemann sees 
in the gonangia of Diplograptus a new indication of relationship 
with the Sertularida. Whatever the relations of the grapto- 
