74 
Description of New or Little-known Forms. 
Class ALG/E. 
Genus GIRVANELLA, Nicholson and Etheridge fil. PI. I., fig. 2 ; 
PI. V., figs. 10-12; PI. VI., figs. 13, 14. 
This genus was instituted by Prof. H. A. Nicholson and Mr. 
R. Etheridge, junr., in 1880 1 , to include certain minute tubular 
organisms, forming pellets from less than a millimetre to more than a 
centimetre in diameter, which occur rather plentifully in the 
Ordovician limestone of Craighead, Girvan, Scotland. Girvanella was 
supposed by the authors of the genus to belong to the Foraminifera, and 
related to Hyperammina , and this view was endorsed by Dr. H. B. Brady 
and other authors. In the opinion of the present writer, the evidence for 
their rhizopodal relationship is very slender, whilst there is a great deal in 
favour of the view already advocated by Rothpletz, Seward, and others 
that they are referable to the Algae. They may either belong to the group 
of the Blue-Green Algae, Cyanophycece, which form the oolitic granules 
in the Great Salt Lake of Utah at the present day, 2 or to the Siphonece , to 
which group Rothpletz referred his Splicer ocodium, which apparently 
formed nodules similar to Girvanella in the Alpine Trias,. 
Since 1880, Girvanella has been recognised as an important agent in 
the formation of many oolitic limestones in England, ranging from the 
Silurian to the Jurassic. 3 Nicholson also identified with this genus similar 
nodular organisms in the Cincinnati limestone of Indiana. 4 
The only accounts of the occurrence of this genus in Australia hitherto 
published are those given by Messrs. R. Etheridge, junr., and G. W. 
Card 5 , who record it from the Carboniferous Oolite of Lion Creek, Stan- 
well, near Rockhampton, Queensland, and from Countv Murchison, New 
South Wales; and by the former author, who described it from the Cam¬ 
brian of South Australia. 6 It is, therefore, of additional interest to re¬ 
cord Girvanella in Victoria as an abundant and important organic agent in 
the formation of limestones belonging to the Yeringian division of the 
Silurian. Previous to the discoverv of Girvanella in the Gippsland area, 
the writer had met with it in the Lilvdale limestone, which is also in the 
Yeringian series, his attention having been drawn to it by the Rev. A. W. 
Cresswell, M.A., who observed that certain portions of the limestone had a 
decidedly oolitic appearance. 7 
Girvanella conferta, sp. nov. 
Plate VI., figs. 13, 14. 
Description. —Filiform tubes having an almost uniform diameter of 
.017 mm. ; closely packed, and arranged in groups in a vermiculate 
manner, either sinuously contorted or wound in more or less parallel 
bundles; segmented at intervals. Forming pellets, sometimes reaching a 
length of 3 mm. or more. 
Observations. —This form differs from G. problematica , Nich. and 
Eth. fil. 8 , in having the tubes in bundles lying side by side, and in being 
segmented at intervals by transverse or oblique partition walls, at which 
1 Mon. Sil. Fossils, Girvan District, vol. i., pp. 28, 24, PI. ix., fig - . 24. 
2 See Seward, A. C., Fossil Plants, vol. i., 1898, p. 124. 
3 See Wethered, E., Geol. Mag - ., Dec. iii., vol. vi,, 1889, pp. 196-200, pi. Ad., figs. 8-11. Also papers b.y 
the same author in Quart. Journ. Geol. Soc., vols. xlvi.-xlix. (1890-1893). 
4 Geol. Mag., Dec. iii., vol. v., 1888, p. 24. 
5 Geol. Surv. Queensland, Bulletin No. 12, 1900, pp. 26, 27, 32. 
6 Trans. R. Soc. S. Australia, vol. xiii., 1890, pp. 19, 20. 
7 See also Proc. R. Soc. Viet., vol. v., n.s. 1893, p. 39. 
a Mon. Sil. Foss., Girvan Dist., vol. i., 1880, p. 23, pi. ix., fig. 24. 
