GHAPTOLITES OF VICTORIA. 
structural details. We anticipate that better specimens will 
throw light on both structure and functions of graptolites ; we 
have, therefore, named this unusual form after Mr. F. Chapman 
whose researches have so greatly advanced Australian palaeon- 
tology. 
Associated graptolites. - Clonograptus tcnellus Linnarsson, Bryograptus sp., 
Didymogr aphis aureus T. S. Hall, I), lalens T. S. Hall, I). latus T. S. Hall, 
Tetragraptus fruticosus (J. Hall) (4br.), T. quadribrachiatus (J. Hall), T. approxi- 
mate Nicholson, T. decipiens T. S. Hall, T. acclinans Keble, Loganograptus 
logani J. Hall. 
Horizon. -Lower Ordovician, Bendigo and Lancefield Series, Zones B5 
and L2. 
Localities. — Holotype, gully near junction of Kangaroo Creek and Lerder- 
derg River, 2 miles below Blackwood (left bank) ; paratype, Antimony Mine, 
Lerderderg River, 1 mile below Blackwood (right bank). 
Tetragraptus decipiens T. S. Hall var. bipatens nov. 
Tetragraptus decipiens. T. S. Hall, Proc. Roy. Soc. Viet., xi (n.s.), 2, 1899, 
p. 168, pi. xvii, xviii. 
(Text figs. 2, 3.) 
Sicula 1.4 mm. long, 0.6 mm. wide. Theca l 1 originates within apertural 
third of sicula and grows downwards at approximately 110° to sicular axis; 
theca l 2 turns in opposite direction and forms with l 1 a funicle enclosing an 
angle of 140°. Thecae l 1 and l 2 bifurcate, giving rise to branches of second 
order, 13 mm. or more in length, normally straight, but usually flexed by 
compression. Secondary branches widen rapidly to 0.8 mm. and maintain 
that width throughout. 
Fig. 2. Tetragraptus decipiens T. S. Hall var. hi patens nov. a. Sicula and 
theca I (No. 25094). b. (?) serrated or irregular apertural margins on branch 
of second order (No. 25058). c. Proximal portion of branch of second order 
showing peculiar arrangement of thecae (holotype No. 25094). x4. 
Thecae, long tapering tubes a little more than three times as long as wide ; 
divergent; overlapping one-fourth of length ; 8 in 10 mm. ; ventral margins 
straight, inclined to axis of branch at 20°. Thecal apertures of holotype either 
acutely dentiform, sigmoidal, concave or straight, according to mode of 
compression. 
Remarks. — In some specimens the sicula has a short incon- 
spicuous nema. The variable aspect of the polypary (text 
figs. 3a-3g), due to mode of compression, is suggestive in regard 
to other quadribrachiate Tetragrapti. The funicle may appear 
angular or straight, and branches of the second order straight 
or flexed. The funicle normally encloses an angle of 140° 
(text figs. 3 a, 3b). Assuming that the whole polypary was 
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