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that the pedicle notch in the Victorian species is more central, and the dimen¬ 
sions much less than in the British species, ^ it is better to regard the two forms 
as distinct. 
Another apparently related form is J. Hall’s 0. tenuilamellata,^ which, 
however, has more numerous growth-lines, sharper ridges, and less depressed 
valves. This species was recorded from the limestone at Lockport, N.Y. 
State (Niagara or Wenlock series). 
Occurrence. —In fossiliferous, shaly Silurian mudstone ; Wombat Creek, 
N.E. Gippslahd (No. 2598). 
Fam. Spieiferid^. 
Genus Spirifer, Sowerby. 
Spirifer yassensis, De Koninck (Plate XVI., Fig. 2). 
Spirifer yassensis, de Koninck, 1876, Foss Pal.Nouv. Galles du Sud, p. 104, 
pi. III., fig. 6. Mem. Geol. Surv. N. S. Wales, Pal. No. 6, 1898, p. 83, 
pi. III., fig. 6. Chapman, 1905, Proc. K. Soc. Viet., vol. XVIII. (N.S.), 
pt. I., p. 16, pi. V., figs, 2, 3. 
Observations. —In the rock specimens from Limestone Creek this typically 
Devonian spirifer is especially abundant. The shells occur in an impure 
limestone, which shows regular bedding due to enormous numbers of this 
brachiopod, together with a larger quantity of mud than usual. The shells 
in this type of rock tend to become almost micromorphic, and are apparently 
stunted by the influx of terrigenous material during the life of the fauna. 
The nature of the rock is shown in plate XVI., fig. 2. 
Occurrence.—Limestone Creek, near Dead Horse Creek (Nos. 2047-69). 
Middle Devonian. 
Fam. CcELOSPiRiD^. 
Genus Coelospira, J. Hall. 
CcELOSPiRA AUSTRALIS, sp. nov. (Plate XXXII., Figs. 43, 44). 
Description. —Holotype. Dorsal valve nearly hemispherical, with a 
straight hinge-line, relatively high area and widely rounded anterior border. 
The slightly convex surface is medially sulcate and ornamented with about 
eight broad, bifurcating riblets, the lateral ones strongly incurved in the 
median area. Both riblets and interspaces are marked with fine raised 
concentric threads. 
Supplementary specimens (Nat. Mus., 792-3) from Cowombat (A. W. 
Howitt coll.) show the ventral valve (paratype No. 792) to be moderately 
convex, with about ten rounded or sub-acute riblets, bifurcating near the 
anterior margin and crossed with concentric, raised growth-lines which become 
slightly tegulate anteriorly. 
Dimensions. —Length of holotype (anterior to extremity of beak), 5 mm.; 
width, 7‘25 mm. Length of paratype, 5 mm.; width, 7 mm. 
Observations. —This species had, many years ago, been identified in the 
museum collection by myself as “ Atrypa hemisphoerica^'' to which form it 
is undoubtedly related. Additional specimens collected by the Victorian 
Geological Survey from N.E. Gippsland enable me to diagnose it as a new 
species of the genus Ccelospira, J. Hall, which genus has not been previously 
recorded for Australia.^ It may be remarked in passing that Davidson 
subsequently referred Sowerby’s species (“ Atrypa liemisphcerica ”) to the 
genus Leptocoelia, but ^ later examination by Hall and Clarke leads them 
^ 0 rugata averages 16 mm., the Victorian species being only 3.25 mm. 
^ Orbicula tenuilamellata, J, Hall, Pal. N. York, vol. II., 1852, p. 250, pi. LIU., fig. 3. Orbiculoidea 
(Schizotreta) tenuilamellata, .J. Hall sp.. Hall and Clarke, ibid., vol. VIII., pt. II., 1894, pi. IVe. figs. 9-11. 
® De Koninck has recorded 1 Atrypa hemisphcerica, Sowerby from the Silurian of Dimtroon, N.S 
Wales ; the description according with the British form and not with our new species. See Mem. Geol. 
Surv. N.S. Wales Pal. No. 6, 1898, p. 26. 
