:92 Frederick Chapman : 



Occurrence. — Silurian (Yeringian). In limestone, Cave Hill, 

 Lilydale. Chiefly from the collection of the Rev. A. W. Cresswell, 

 M.A. 



Genus Straparollus, Moutfort. 



Straparollus debilis, sp. nov. (Plate IV., Fig. 34 ; Plate VI., 



Fig. 56). 



Description. — Shell depressed, subcircular. Whorls about five, 

 rounded, coiled in an irregular spiral and increasing slowly in 

 "width. Surface relieved with fine threadlike lines of growth, which 

 are only slightly curved. Aperture subcircular. 



Dimensions. — Greatest diameter, about 15 mm. ; measurement at 

 right angles about 14 mm. Height of shell, 4.25 mm. 



Observations. — This species has a somewhat vermiform appeal'- 

 ance from its weakly and irregularly coiled shell. Its nearest 

 •■specific analogues seem to be S. ruclis, J. Hall sp.,^ and S. hecale, 

 ■J. Hall sp.,' the former from the Middle Devonian (Hamilton group) 

 of West Bloomfield, New York, the latter from the Upper Devonian 

 •(Chemung group) of Rockville, New York. S. rudis is a larger 

 shell and increases rather rapidly in its later whorls, whilst 

 S. hecale is more regularly discoidal in outline. S. annulatus, 

 Phillips sp.,^ from the Devonian of Newton, Devonshire, is another 

 related form, distinguished by its discoidal outline and prominent 

 growth-lines. 



De Koninck has figured a related form to the above from the 

 Silurian at Rock Flat Creek, east side of Maneero, New South 

 Wales, under the name of Euomjjhalus solar ioides.'^ This species 

 differs in having an ornament of transverse tubercles instead of 

 striae as in the Victorian species. 



Occurrence. — Silurian (Yeringian). In brown mudstone. Rud- 

 dock's Quarry, near Lilydale. Collected by F. Chapman. 



Fam. TURBINIDAE. 



Genus Omphalotrochus, Meek. 

 Omphalotrochus globosum, Schlotheim sp. (Plate IV., Figs. 35, 36). 

 Trochilites globosus, Schlotheim, 1820. Petrefactenkunde, p. 162 

 Euomphahis funatus, Sowerby, 1823, Min. Conch., vol. V., p. 71, 

 pi. 450, figs. 1, 2. Id., 1839, Silurian System, p. 626, pi. XII.. 



1 Eaomphalus (Straparollus) rudis, J. Hall. Tom. supra cit., p. 68, pi. xvi., figfs. 6, 7. 



2 KuomphaUis (Slraparolluis) heealf, J. Hall. Ibid., p. 59, pi. xvi., figs. 10-14. 



3 Euomphalus annulatus, Phillips. Pal. Foss. Cornwall, Devon and W. Somerset, 1841, p. 138, 

 pi. Ix., fig. 172. 



i Mem. Geol. Surv. N. S. Wales, Pal. No. 6, 1898, p. 30, pi. i., fig. 5. 



