46 
GRAPTOLITES OF AUSTRALIA 
He collected graptolites from a number of places in the 
area which were submitted to T. S. Hall for identification. 
He obtained Monograptus in black slates in the valley of 
the Thomson for half a mile above the Jordan-Thomson River 
junction. Regarding these graptolites he quotes T. S. Hall, 
who states that “Monograptus seems to be the only genus 
represented, and, as far as the material allows of careful 
examination, only one species is present. With some hesita- 
tion, owing to the imperfection of the material, I identify 
this as M. dubius Suess. . .” From a spur one mile south of 
the Thomson- Jordan junction. Hall identified M. cf. dubius 
and M. sp. Commenting on the forms from a spur between 
Little Boy’s and Bell’s Clear Creek, he remarked on their 
poor preservation and that they appeared to belong to the 
sub-genus Pristiograptus. Certain specimens had thecae of 
the “priodon’’ type. The forms from a spur a mile south of 
the last locality were likewise inconclusive. 
From a locality near the last one, two specimens (Nos. 547 
and 548) submitted to him provoked considerable comment. 
“No. 547,” Hall says, “is a Monograptus, and is therefore a 
Silurian form, whereas No. 548 is a Didymograptus, having 
the aspect of B. caduceus. The cast of the sicula can be 
clearly seen, and the reverted apertural denticles of the 
thecae are visible. Of the generic position of the fossil there 
can be no question. The matrix, an indurated micaceous 
mudstone, appears the same as that of many of the other 
specimens from the same spur, but I feel convinced that the 
presence of the Lower Ordovician type in association with 
Monograptidae is an error due to human agency. With the 
exception of this fossil, the whole of the rest of the fossils 
(Nos. 522-538 and 547) are of Silurian age.” 
To this he added a footnote. “In face of Mr. Baragwanath’s 
personal assurance that there was no confusion of localities 
in these two specimens, but that both came from the same 
block of stone, I have requested permission to re-examine 
them. I see no reason to alter my opinion as to their generic 
position. I have, moreover, explained the case to Mr. F. 
Chapman, a.l.s., and he has examined the supposed Didymo- 
graptus. He allows me to say that he agrees with my identi- 
fication. Further specimens are urgently required from this 
locality as the inferences to be drawn are too important to 
rest on a couple of very indistinct fossils.” 
In view of the above, a further search was made in the same 
place and from the resulting specimens, T. S. Hall identified 
Monograptus cf. dubius Suess, M. cf . crenulatus Torn, (genus 
