FEESHWATEE SHELLS OF AUSTEALIA. 309 



p. 295). The IT. mutahilis of Lea has this peculiarity also. The 

 TT. depressiis of the ' Conchologia Iconica,' fig. 81, is a very dis- 

 tinct species, and approaches certain varieties of TJ. amliguus, the 

 specimen figured being from Tasmania. 



140. TJnio atjstralis {Lamarck), Fhilippi. 



Unio australis, Lamarclc, Anim. s. Vert. ed. 2, vol. vi. p. 546; Hartley, 

 Recent Shells, p. 192, pi. xxi. fig. 25; Philippi, Abbild. vol. iii. 

 p. 81, pi. V. fig. 5. 



Non Unio australis, Lamk., Kuster, Con.-Cab. p. 230, pi. Ixxvii. fig. 6. 



Far. = Unio moretonicus. Reeve, Con. Icon. fig. 118. 



Hab. Australia. 



This species, T7. halonnensis, Conrad, TT. amliguus, Parreyss, 

 TJ. viitatus. Lea, TJ. Danellii, Villa, and TJ. profugus, Grould, are 

 very difficult to define. The second and third, I think, are cer- 

 tainly the same. TJ. australis, as determined by Philippi, is very 

 like the TJ. ShiittlewortJiii of Ijea,hutra.th.er less eloagsite, agreeing 

 vfith it, however, in the slight ventral sinuation and the narrower 

 anterior end. 



Lamarck's diagnosis is so brief, that it is utterly impossible to 

 know what species he had before him. I therefore adopt 

 Philippi's idea of it. He was the first to describe and figure a 

 shell which he believed to be the TJ. australis. Subsequently 

 Kiister, in the ' Conchylien-Cabiuet,' describes and figures under 

 this name a shell which appears to me difterent from that repre- 

 sented by Philippi. Kiister makes no reference to the latter 

 author's work. The figure in the ' Conchylien-Cabiuet ' repre- 

 sents a specimen with a coarsely concentrically striated surface 

 and scarcely attenuating anteriorly. On the contrary, Philippi's 

 figure is more finely striated, and the hinder end is considerably 

 broader than the anterior. 



141. Unio ambigtjus, Farreyss. 



Unio ambiguus, Parreyss, Philippi, Abbild. vol. iii. Lieferung 2, 1848, 



p. 47, pi. iii. fig. 2; Reeve's Con. Icon. fig. .355 ; Kilster's Con.-Cab. 



pi. Ixxix. fig. 2. 

 Unio balonnensis, Conrad, Proc. Acad. Nat. Sci. Philad. 1850, p. 10; 



id. Journ. Acad. Nat. Sci. Philad. ser. 2, vol. ii. p. 295, pi. xxvi. fig. 3 ; 



Lea, Synopsis, ed. 18/0, p. 103, as var. of depressus, Lamk. 

 Unio philippianus, Kiister, Con.-Cab. p. 235. 

 Unio vittatus, Lea, Proo. Acad. Nat. Sci. Philad. 1859, p. 153 ; Reeve, 



Con. Icon. fig. 83. 



