1863.] ON NEW AUSTRALIAN FRESHWATER SHELLS. 417 



cults ; apertura ovato-acuta ; labia incrassato, flexuoso ; labro 

 acuta, margine arcuata. 

 Long. 6 lines, lat. 3 lines. 

 Hab. Arnheim's Land {Call. Angas.). 



A neat olive-coloured species, somewhat resembling in form the 

 British Aplexa hypnorum, but without the polished exterior of the 

 latter. 



10. Physa concinna. Ad. & Ang. 



P. testa ovata, hnperfarata, salidiuscula, cornea ; spira brevi, 

 acuta, apice interdum papillaso ; anfractibus quinque, convexius- 

 culis, transversim striatis ; apertura acuta-ovata ; labia incras- 

 sata, spiraliter valde tortuosa ; labro intus incrassato etfusco 

 tincto, margine acuta, arcuato. 



Long. 6 lines, lat. 3 lines. 



Hab. Arnheim's Land (Coll. Angas.). 



A pale horn-coloured, somewhat solid species, with a moderately 

 elevated spire, acute (not eroded) at the apex, and with the terminal 

 whorls sometimes papillary. 



11. Physa (Amerta) reevii. Ad. & Ang. 



P. testa ovali, postice abrupte truncata, imperforata, cornea; spira 

 plana, tenui; anfractibus quatuor, plants, ultimo permagno, 

 postice acute angulata, transversim obsolete striata ; apertura 

 oblongo-truncata ; labia antice valde tortuosa ; labro postice 

 angulata. 

 Long. 6 lines, lat. 4 lines. 

 Hab. Arnheim's Land {Coll. Angas.'). 



We have much pleasure in dedicating this singular species to Mr. 

 Lovell Reeve, who has evinced much interest in the shells of this 

 group. The last whorl is acutely angulate posteriorly, and the spire 

 is tabulated, giving to the shell a peculiar truncate appearance. 



12. Physa (Ameria) bonus-henricus, Ad. & Ang. 



P. testa ovata, rimata, tenui, cornea; spira vix elata, plana; 

 anfractibus tribus, planis, postice angulatis., ultimo magna, in- 

 flato, ventricoso, postice subangulato, longitudinaliter plus mi- 

 nusve plica to ; apertura ovata; labia tenui, subtortuoso; labro 

 simplici, margine arcuato. 

 Long. 4 lines, lat. 2^ lines. 

 Hab. Arnheim's Land {Coll. Angas.). 



This is a small inflated species, with a short truncate spire. We 

 have dedicated it to the founder of the section Ameria, a gentleman 

 well known for his deep researches in conchology. 



yj 13. Unio (Alasmodon) stuarti, Ad. & Ang. 



U. testa transversim elongato-ovata, tenui, compressa, epidermide 

 olivaceofusca induta, postice corrugatoplicata, latere antico 

 breviore rotundato, postico longiore oblique subtruncato, mar' 

 gine ventrali regulariter arcuato; umbonibus parvis, erosis, den' 



Proc. Zool. Soc— 1863, No. XXVII. 



