74 COXTKIBUTIOXS FOR SYSTEMATIC CATALOGUE AQUATIC SHELLS. 



Beddomeia Launcestonensis. Johnston. 

 Plate I. Fig. 2. 



Amnicola Launcestonensis, Johnston. Pro. Royal Soc. Tas., 

 1887. ^jinna/ with the foot of medium size, opaque white, 

 teutaculaj extremely long and pointed, of a darlc lead grey 

 colour, muzzle broad, wrinkled and prominent, the same 

 colour as the teutacula?, but freckled with a darker shade. 

 The eyes are distinctly visible when the animal is in motion. 



Lingnal membrane is somewhat long but narrow, with about 

 100 close set rows of very minute teeth, the formula of which 



is as follows:—-^ — ^-— ^ ! 8 ! 18 to 20. 



Plate IV. Fig. 4. 



The median tooth is much arched, has a deep indentation 

 on the upper margin, and the lower central lobe is not V3ry 

 pronounced. The first lateral has a rounded protuberance on 

 the upper inner margin at its juncture with the peduncle 

 and the denticles are pointedly serrate. The second lateral 

 is curved, angular, and much thickened behind, and has 

 18 to 20 extremely fine rounded denticles. The third is not 

 nearly so much arched and has also a prominent lump on the 

 inside margin. 



Operculum, thin yellowish horn, pancispiral. 



Habitat — South Esk River. 



Var. A. TUMIDA. 



Shell, thin, greenish horn colour, marked with fine lines of 

 growth, perforate. Aiwrtnre, more regular in outline than in 

 mature typical examples; outer lip thin, not reflexed. 

 Lcnfjth, 4; breadth, 3 mill. 



Habitat — The Great Lake. 



Var. B. MINIMA. 



Shell, very much smaller than type, black, granular on 

 surface, perforate. Aperture, contracted above. 

 Length, 2i ; breadth, 2 viill. 



Habitat — In a small stream near Scottsdale. 



The typical shell is extremely abundant in many parts of 

 the South Esk ; it more especially loves the (|uiet secluded 

 lock jtools on the margins of the swiftly running portions of 

 the stream. About the Cataract near Launceston it is verv 

 plentiful, often in company with the form I have named 

 P. ]V(/()dsii ; in the First Basin and higher up the river it is 

 more globose in form and of a paler colour, and thus in many 

 respects approaches the variety collected in the Great Lake. 

 The variety viiniina will require further examination as it is 

 possible that the animal may l)e different to the type ; should 

 such be the case it will be necessary to rank it as a siiecies. 



