590 ON THE GENUS DIPHLKBIA, 



dorsal line crossed at one-fourth from apex by a flattened trian- 

 gular or diamond-shaped mark; 4-7, like 3, but much darker, 

 dorsal line thicker and apical mark less regular; sutures black, 

 wider on sides, a long black bar low down on each side of 4-6, a 

 short bar on 7; 8, dark brown, paler on sides; 9, almost black 

 basally, touched with brown apically and on sides; 10 very pale 

 brownish, with l>lack dorsal line. Appendages 1 mm., 

 blackish, conical, sharply pointed. 



Hah. — Rocky Creek, near Caroda; Nandewar Ranges, N.S.W.; 

 also (less commonly) Fallal Creek, near Bingara, N.S.W. (Decem- 

 ber, 1910). 



Types: (J 9, and series of cotypes in my collection, taken by 

 myself, in above localities. 



The two localities given are only a few miles apart, and both 

 are tributaries of the Horton River, which joins the Gwydir 

 near Bingara. The insect frequents only the rocky parts of the 

 creeks, and is absent from the lower part of Fallal Creek, and 

 from the Horton River itself. It is one of the most beautiful 

 and brilliant insects known to me, the blue of its body far out- 

 rivalling the colour of D. lesto'ides, itself a brilliant insect. I have 

 therefore chosen the name nympho'ides (^Grcek vvfxcfuj, a bride) in 

 allusion to its beauty. 



Comparisofi of the. Four Known Species. 



The four known species, D. lestdides Selys, D. euphcedides 

 Tillyax'd, D hybriddides, n.sp., and B. riymphdides, n.sp., are all 

 closely allied, and form a homogeneous and natural Australian 

 genus. The following table gives the most important differences 

 for the males : — 



