GRAPTOLITES. 99 
3. <A frond with small disc and somewhat slender stipes. One side preserves the 
usual character of four stipes, while the other has but three. 
4. A frond which is abnormally developed; one side preserving the four stipes with 
the disc, while on the other side the funicle is apparently extended in a single 
stipe only. 
Formation and Locality.—Shales of the Quebec group; Point Lévis. 
The G. Logani is the only species with numerous unbranched stipes 
which we know of at this time in the Quebec group. All the other species 
with more than eight stipes, have them branched beyond the commence- 
ment of the cellules. In the Hudson River formation, however, we have 
a single analogous species, the G. multifasciatus. In that one the stipes 
are forty or more in number, and are apparently simpler after they 
become celluliferous. 
In the progress of development of the graptolites of this type, we have 
traced them through the two, four, and eight-stiped forms. Those with 
two stipes have never shown the cup or disc ; while some of the latter 
two forms have discs, and others apparently never possessed this appen- 
dage. ‘The subdivision into stipes appears to go on by a regular duplication 
of the parts; and the stipes in perfect forms are bilaterally arranged, 
beginning with those having two; which proceed, one on each side, from a 
rootlet. With the exception of G. fruticosus, the four-stiped forms origi- 
nate from a minute radicle; while on each side of this centre, the body 
extends a short distance in the funicle, which is not celluliferous ; and then 
subdivides equally, no cellules occurring below the division. In the next 
form, the funicle is divided at cach extremity as before, and again divided 
or bifurcated below the origin of any cellules. Were this mode of sub- 
division to continue, the next step in the development would give us sixteen 
stipes ; but we have no form of this kind in the collections. 
Tn the next form, with simple stipes, we find the G. Loganz, which pre- 
sents a wide variation in the number of stipes; so varied indeed that the 
two extremes might, if examined separately and without the intermediate 
forms, be regarded as two distinct species. ‘The variation in the number of 
stipes in this species extends from eighteen to twenty-five : some divisions 
of the funicle are equally, and others unequally developed in the number 
of stipes which proceed therefrom. 
