126 THE FRESHWATER MOLLUSCA OF VICTORIA 
1894 Gundlachia beddomei Petterd, MS. Hedley, op. cit., p. 513, pi. 24, 
figs. 4-6. 
1895 Id. Hedley, Pr. Linn. Soc. N.S.W., (2 ser.), ix, p. 464. 
1920 Gundlachia petterdi Johnston. May, Pr. Roy. Soc. Tas., p. 71. 
1921 Id. May, Check-list Moll. Tas., p. 91. 
1923 Id. May, 111. Index Tas. Shells, pi. 41, fig. 25. 
1932 Id. Cotton and Godfrey, S. Aust. Nat., xiii. No. 4, p. 164, pi. 3, 
fig. 12. 
1936 Id. Cotton, S. Aust. Nat., xvii. Nos. 1-4, p. 84, fig. 42. 
Size of Type. — Length, 2 -5-3 mm.; breadth, 1-5-1 75 mm. ; 
height, 5- 75 mm. 
Localities. — ^Heidelberg (Rev. W. Fielder) ; Alphington 
(J. Searle) ; Blackburn Lake (A. L. McLachlan). 
Vernacular Name. — Petterd ’s Freshwater Limpet. 
Observations. — Shell minute, thin, pale horn in colour, 
diaphanous, spirally oblong in two distinct tiers, apex 
obliquely inclined posteriorly, concentrically striate and 
crossed by fine, radiating lirae, apical tier more incrusted 
with confervoid matter, and appearing partially and 
obliquely exserted upon the basal tier ; projecting portion of 
apical tier as well as one-third of the basal one closed by 
a fiat horizontal plate, all in the plane of the original 
aperture of apical tier ; outer aperture broadly ovate ; lip of 
basal tier continuous, although modified at junction with 
apical tier; inner aperture semi-circular, and determined 
to a great extent by the original aperture of apical tier ; inner 
lip with slightly raised rim continuous, simple. The juvenile 
shell is simple, and resembles the common Ancylus. 
G. petterdi is easily recognized. It is common on dead 
leaves and sticks. The species is also recorded from Tas- 
mania and South Australia. Ancylus woodsii Johnston is 
undoubtedly the immature form. 
The genus Gundlachia is found in America and in Cuba. 
LAMELLIBRANCHIATA. 
Family CORBICULIDAE. 
Genus CORBICULA Megerle, 1811. 
Corbicula angasi Prime. 
(PL IV, Fig. 34.) 
1864 Corbicula Angasi Prime, Jour, de Conch., xii, p. 151, pi. 7, fig. 6. 
1878 Cyrena Angasi (Prime). Sowerby, Conch. Icon., xx, pi. 17, fig. 90. 
1879 Corbicula rivina Clessin, Conch. Cab., p. 139, pi. 25, figs. 3, 4. 
