C8 CONTRIBUTIONS FOR SYSTEMATIC CATALOGUE AQUATIC SHELLS. 



Flanorhis cathcarti mihi. M.S. 



Habitat — Upper Ouse River (Masters). Great Lake (^Inme). 



This species was first discovered by Mr. George Masters, oi 

 the Syducy Museum, in 1864. It is the largest species found 

 here, and the least understood. The three type specimens, 

 from one of which the drawings are taken, were lately sent 

 me for comparison, by Mr. J. Brazier, and I find that what has 

 been generally taken for vicridionalis by conchologists here, 

 is not in reality so, and that the form described by the Rev. 

 Tenison- Woods, under the name of V. TasDuniicns, is quite 

 another kind. This species may be known by its comparatively 

 large size, sharply carinated periphery and depressed 

 aperture. I have not seen this shell from any locality but 

 those given. It has no representative in Australia. 



I am informed by Mr. Brazier that the rhnuirhis Austra- 

 lianus, Martens, (Paetel, Cat. der Conch, 1873), is simply a 

 catalogue name, the shell never having been described. 



Planorbis Tasmanicus. Tt'uison- Woods. 



Plate II. Figs. 8 and 9. 



Planorbis Tasmanicus. Tenison- Woods. Pro. Roy. Soc. 



Tasmania, j). 70, 187G. 

 IlahUat — Circular Head, South Esk, and Liftey rivers. 



A minute, flatly discoidal shell, which is widely umbilicated 

 above and below, freely showing the whorls on both sides ; 

 it is but obscurely angled below the periphery with an ovate 

 aperture. It is totally distinct from the preceding, as the 

 illustrations will clearly show. The Rev. Teuison-Woods 

 withdrew his specific name, as he thought that he liad 

 described the same form as Mr. Bi-azier (Pro. Royal Soc, 

 Tas., 1878). 



At Circular Head I have collected it in vast numbers, 

 harbouring among acquatic weeds on the surface of small 

 pools, and in marshes in the same neighbourhood. About 

 Launceston it is not abundant, being only occasionally 

 obtained in the South Esk, here the smaller P. Scottiana 

 seems to take its place. The nearest Australian form is P. 

 Brazier i, Clcsscn, from Ipswich, Queensland, but that species 

 is more acutely keeled and even flatter. 



Planorbis Atkinsoni. Johnston. 



Plate II. Figs. 6 and 7. 



Planorbis Atkinsoni. Johnston. Pro. Roy. Soc. Tasmania, 



1878. 

 Habitat — South Esk River. 



