276 
of 1.5 mm. maintained throughout. The biserial portion bears about 
10 thecae in 1 cm., of which about* 12 are spined. Thecae strongly curved 
inwards and laterally. TJbe variety is intermediate between the typical form 
and var. spinifer Elies and Wood. From the former it differs by the 
presence of more than one spine on each side of the biserial portion, 
by the greater width of this part, and by the fact that it does not 
broaden continuously from sicula to bifurcation. From var. spinifer 
it differs in not having all the thecae of the biserial’ portion spined, and in 
this part not being, ovate in outline, [to examples.] 
Dicranograptus hians , T. S. Hall. 
(1 See Proc. Roy. Soe. Viet. 18 (1905), p. 24, pi. 6, fig. 6). 
[3 complete, and 2 imperfect, doubtful examples]. 
Dicranograptus nicholsoni , Hopkinson. 
(See Hall, T. S.; Proc. Roy. Soc. Viet. 18 (1905), p. 24, pi. 6, fig. 7). 
[4 examples]. 
Diplograptus ingens, sp. nov. 
Plate xxxiv., Fig. 7. 
Hydrosome very large, expanding from a pointed sicular region for 
about 15 mm., when it reaches a width of 6 or 7 mm. Thence it 
very slowly narrows, and at about 40 mm. from the sicula is about 4 or 5 mm. 
wide. It then gradually increases to a width of 5 or 6 mm. The 
anti-sicular end is abruptly truncate. Virgula distinct, but slender; free 
for about 1 mm. Virgelltai about 1 mm. long. Thecae 9 or 10 in 10 mm. 
They appear to have the shape of those shown by Tap worth in his D. 
perexcavatus .* They consequently at times show a series of triangular 
denticles with the apertural margins normal to the virgula, while in other 
cases on the same specimen the outer margin is hollowed out much as in 
CUmacograptus . The thecae as a whole are inclined at about 30 or 40 deg. 
None of the specimens show further details. The great size of the 
species is not due to extreme compression, as examples of other species 
on the same slabs are not abnormal. 
There are some slightly smaller specimens present with parallel sides 
and with an extreme width of 4 or 5 mm., which I think are merely 
varieties of this form. 
[55 examples]. 
Diplograptus foliaceus, Murchison. 
The variety occuring here has about 13 thecae in 10 mm., as opposed 
to 8 or 9 in the New South Wales examples I have elsewhere figured 
and described; otherwise the specimens agree. 
[72 examples]. 
Diplograptus cf. aculeatus, Fapvvorth. 
A single example agrees well with Fapworth's species, but is not 
distinct enough for exact determination, and the sicular and anti-sicular 
ends are imperfect. The thecae number nearly 11 in 10 mm. (28 in an 
inch), thus agreeing with Fapworth’s maximum. Their shape is not 
very clearly shown. Doubt as to the identity of the present specimen 
arises from the fact that the test is fairly thick and not of the extreme 
tenuity described by Fapworth. 
( * Ann. Mag. Nat. Hist. ser. V. (1880), pi. 5, fig 25d. 
