82 CONTRIBUTIONS FOR SYSTEMATIC CATALOGUE AQUATIC SHELLS. 



distinct. All writers upon the subject give special 

 prominence to the general confusion into which the 

 Australian forms of Unionidtv have fallen, principally 

 caused bv slight variations and imuiature examples having 

 been described as distinct species ; this has been renderedmore 

 confusing bv erroneous habitats often given, and the now 

 well known incorrectness of many of the localities recorded 

 in the " Conchologia Iconica" has also caiised several recent 

 authors to fall into error. 



After carefully studying the subject and comparing 

 numerous specimens from almost all parts of Australia with au 

 extensive series collected in our streams, I have come to the 

 conclusion that our form, that has been known to 

 conchologists for so many years, is in reality an undescribed 

 species, so that it is therefore necessary to bestow upon it a 

 specific appellation, in doing which I have embraced the 

 opportunity of recording my obligation to Mr. W. Legrand 

 for my early instruction in the study of shells. 



In any case the specific term Moretonicus, is a geographical 

 misnomer, and, to my mind, it should be altered if only for 

 that reason. The figure given by Reeve, No. 118, very closely 

 represents a variety of U.Mcnziesii, Gray, of New Zealand, from 

 rapid flowing streams when it is much shorter and thicker than the 

 more typical form. In U. LeqrancU the teeth are small and 

 the interior is clear bluish white with faint iridescence of pink 

 and green. Its home is the sandy beds of shallow clear 

 running streams, where, as in certain parts of the South Esk 

 and the St. Paul's Rivers, it can be obtained in considerable 

 numbers. As is the case with many species of the genus, the 

 sexes differ in the outline of the shell. 



Plate 1. 



Fig. 1. Brazier ia Tasvianica, Tc7iison- Woods, Arthur River. 

 2. Beddomeia Launcestonensis, Johnston, South Esk River. 

 ^3, ,, ,, \o.Y. minima, Scottsdale. 



„ 4-5-G. rianorbis mcridionalis, Brazier, Ouse River. 

 ,, 7. Beddomeia Belli, milti, Ht-azlewood River. 

 ,, 8. ,, Jlulli, mild, „ ., 



,, 9. Potamopyrgus marginala, mihi, near Wliyte River. 

 „ 10. „ Smitlii, viilii, Waratah River. 



„ 11. Beddomeia Tasmaniea, Tenison- J/'(Wj,Gould'sCountry. 

 „ 12. Potamopyrgiis Woodsii, mihi, South Esk River. 



Plate II. 



„ 1. Tatea riifilabris, A. Adams, River Don. 



„ 2. A suminea Tasmaniea, T. ir^^^y, Brown's River. 



„ 3. Ilydrobia Uirbinata, mihi. River Styx. 



