GRAPTOLITES OF VICTORIA. 
outlined by strands. Subvertical sides of consecutive pairs of rhombs from 
an outer and inner angle ; thecae project from the outer angles, successive 
thecae being on opposite sides of the polypary, and separated by ihombic 
interspaces. Apertures subangular, each with a short blunt spine. Longi- 
tudinally throughout the polypary are two septal strands, one zigzag (obverse 
aspect), and the other straight (reverse aspect). 
Associated graptolites. — C. uncinatus, sp. nov., C. missilis Keble & Harris, 
C. t abut if crus Lapworth, Diplograptus carnei T. S. Hall, Leptograptus eastonensis 
Keble & Harris, L. flaccidus J. Hall, etc. 
Horizon. — Upper Ordovician, Bolinda Series. 
Locality. — About 10 chains West of Jordan River where it runs under 
Yarra Track between Matlock and The Oaks. 
Family MONOGRAPTIDAE Lapworth 1873. 
Genus MONOGRAPTUS Geinitz 1852. 
Monograptus aplini T. S. Hall, emended Keble and Harris. 
M. aplini T. S. Hall, Viet. Grap., Pt. IV, Proc. Roy. Soc. Viet., Vol. 
XXVII (n.s.) Pt. 1, p. 114, 1914, pi. xvii, fig. 17. 
(Plate XXII, figs. 2a~2i, and text fig. 7.) 
T. S. Hall’s original description (8) is as follows : “Very 
minute, curved toward the ventral side. The most complete 
specimens form an open U-shaped figure. Thecae 18 to 20 in 
10 mm. ; apparently coiled in a rounded mass, and opening 
laterally. Sicula about 1 mm. long and narrow.” He adds 
that “M. aplini is closely allied to M. exiguus Nicholson, and 
M. nodifer Tornquist, but its minute size separates it from 
them.” Hall’s type is from Keilor, Victoria. The type, as 
figured by him, does not show the characteristic form of the 
polypary. On this account, and influenced by the words 
“very minute” in Hall’s diagnosis, we failed at first to identify 
our specimens with M. aplini. We have refigured the type 
specimen (PI. XXII, fig. 2a), together with another specimen 
from the same slab (PI. XXII, fig. 2 h.) 
Although M. aplini resembles M. exiguus Nicholson and 
M. nodifer Tornquist (see Elies and Wood, 5) in general appear- 
ance, we are convinced after examining hundreds of specimens 
that the thecae of M. aplini are curved tubes opening, as Hall 
observes, laterally, the apparent coils being due to compression 
of the apertural margins. Specimens from Enoch’s Point are 
usually more robust than those from Keilor and have more 
widely spaced thecae (about 14 in 10 mm.). 
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