128 
THE FRESHWATER MOLLUSCA OF VICTORIA 
1920 Sphaerium macgillivrayi Smith. May, Pr. Roy. Soc. Tas., p. 68, 
pi. 9, fig. 1. 
1921 Id. May, Check-list. Moll. Tas., p. 21, No. 152. 
1923 Id. May, 111. Index Tas. Shells, pi. 9, fig. 9. 
1923 Sphaerium tasmanicum (Ten. Woods). May, 111. Index Tas. 
Shells, pi. 9, fig. 9. 
1936 Sphaerium macgillivrayi Smith. Cotton, S. Aust. Nat., xvii. Nos. 
1-4, p. 85, fig. 48. 
Size of Type. — Length, 9 mm.; breadth, 7 5 mm.; height, 
5 mm. 
Localities. — Melbourne University Lake (Nat. Mus., 
Melb.) ; Carrnm, Tarraville, Longford (T. Worcester) ; 
Meredith, Anakie (J. H. Young) ; Dandenong (J. A. Ker- 
shaw) ; Moorooduc (Rev. G. Cox) ; Birregurra (A. C. 
Nilson) ; N. Portland (C. J. Gabriel). 
Vernacular Name. — Tasmanian Orb Shell. 
Observations. — A thin, fragile shell, subquadrate, ventri- 
cose, shining, fleshy-yellow, striate, white inside, with lines 
of growth indicated by three or four silver-like bands of 
colour; umhones prominent. In South Australia Cotton has 
recorded this species under the name of S. macgillivrayi 
Smith, but I have no doubt this name is synonymous with 
the earlier S. tasmanicum Ten. Woods. In Tasmania, May 
regards tasmanicum and macgilUvrayi as distinct, remarking 
that the latter is less round and has more prominent umbones, 
variations discernible in the Victorian form. 
Sphaerium problematicum sp. nov. 
(PI. IV, 36, 36a, 36b.) 
Shell thin, hyaline white, nearly equilateral, moderately 
inflated, transversely ovate; anteriorly narrower and more 
acuminate than at the posterior end. Umbones fairly promi- 
nent. Surface of shell bearing minute concentric striae. 
Internally white. 
Size of Type. — ^Length, 4 75 mm.; breadth, 7 mm. 
Locality. — Murray River, near Merbein. Collected by F. 
S. Colliver. 
V ernacular Name. — The Oval Orb Shell. 
Observations. — A distinctive little species somewhat 
approaching S. tasmanicum Ten. Woods, but more ovate in 
form. 
Type in the National Museum, Melbourne. Reg. No. 71231. 
