310 . ME. E. A. SMITH ON THE 



Hob. Balonne and Bogan rivers (Cow ra^) ; Eiver Onka-paringa, 

 at Noarlunga ( JfbZmew^, U. vittatus). 



The name amhiguus was published by Philippi in the second 

 part of the third volume of his ' Abbildungen,' which was com- 

 pleted in 1851. The Lieferung in questiou, however, appears to 

 be undated ; but a private mark upon the copy in the British- 

 Museum library shows that it was obtained during the year 1848, 

 or two years previous to the publication of Conrad's Tf. haJonnensis. 



Philippi's figure does not represent the full size to which the 

 species attains, for one specimen in the Museum from Melbourne 

 has an extreme diameter of 4^\ inches. The nacre is described 

 as bluish, becoming in the umbonal region brassy or flesh- 

 coloured, or pale flesh-colour with brass-coloured stains. Judg- 

 ing from the Museum series, as a rule, the lower or ventral half 

 of the shell is bluish v.hite, and the umbonal region, and, indeed, 

 frequently the upper half of the shell, is stained with a brassy- 

 brown colour. The posterior eud, especially upon the muscular 

 scar, displays the greatest iridescence. 



I fail to discover any essential diff'erence in the TJ. vittatus of 

 Lea. The types in the Museum from Cuming's collection are 

 of a paler and yellower colour than usual ; and consequently two 

 or three of the dark concentric zones marking periods of growth 

 contrast more conspicuously than in deeper-coloured specimens. 

 The form is the same, the sculpture perhaps a trifle finer, and 

 the surface therefore rather smooth. The teeth ofi'er no dif- 

 ferences ; and the interior, although described by Lea as white, 

 is in reality bluish white on the lower half and brassy brown 

 towards the umbonal region, just as it is in the normal form 

 represented by Philippi. 



Kuster changed the name amhiguus to philippianus, because 

 the former had been employed for another species which he in- 

 cludes in the genus Unio, although described by Lamarck as a 

 Gastalia. 



142. XJjSTo PEOFUGTjs, Gould. 



Unio profugus, Gould, Proc. Bost. Soc. Nat. Hist. 1850, vol. iii. p. 295 ; 



id. Explor. Exped. p. 429, Atlas, pi. xxxviii. fig. 543b; id. Otia 



Conch, p. 88. 



Hal. Hunter Eiver, IST. S. Wales. 



This species appears to be rather narrower than Z7. amhiguus, in 

 which respect it approaches Z7. Shuttleworthi oi'Le2i.\)ut it does not 



