56 



Unio Bednalli, spec. nov. 



Transversely elongate-oblong, about twice as long as broad ; 

 tbin, sub-compressed. Epidermis tbick, dark brown, radially 

 striated, and concentrically striated between tbe folds of 

 growtb, wrinkled in tbe flattisb postero-dorsal region. Umbones, 

 at about tbe anterior tbird, moderately inflated; anterior 

 margin rounded, ventral nearly straigbt, posterior obliquely 

 truncate. Teetb as in Z7. Sfuartii. Interior of valves iridescent 

 bluisb, radiately striated. Lengtb, 79 ; breadtb, 40 ; tbickness, 

 30 ; anterior side, 23 ; posterior, 56 millimetres. 



Hah. — Eiver Adelaide, at tbe ford (E.T.) ; Yam Creek, at 

 Grlencoe (Mr. J. B. Eobinson, coll. Mr. Bednall). 



Bemarhs. — Z7. Bednalli is related to JJ. Stuartii, from wbicb 

 it differs in being more tumid, less inequilateral, and in its 

 truncated, not acuminate, posterior margin. Tbe epidermis of 

 young sbells of U. Stuartii is of a pale brown colour, wbilst 

 tbat of U. Bednalli is always blackisb-brown. 



I bave mucb pleasure in naming tbis form after Mr. AV. T. 

 Bednall, to wbom science is indebted for bringing to notice 

 many interesting marine species from tbe ]N'ortbern Territory 

 and otber parts of Australia. 



Unio Angasi, Eeevc. 



Bef.—Icon. Concli., t. 55, f. 282, 1867. 



Hah. — Strangway's Eiver, tributary of tbe Eoper (Stuart 

 Exped.). 



Unio (afl.) Angasi. 



Hah. — Ponds by tbe Eiver Adelaide at tbe ford and tribu- 

 taries of tbe Eiver McKinlay (E.T.). 



Tbis form differs from Angasi in being more depressed and 

 more arclied bebind tbe umbones ; tbe interior is bluisb 

 iridescent. Leicbardt recorded Unios from tbe Soutb Alligator 

 Eiver, " smaller tban tbosc in the Eoper;" these may belong to 

 the same species inhabiting the McKinlay Eiver. 



Mycetopus rugatus, Soicerhy. 

 Bef. — Beeve'slcon. Condi., 1. 17, f. 7; B. A. Smith in "Voyage 

 Erebus," t. 4, f. 1. 



Hah. — A'ictoria Eiver (Capt. Wickham). 



