6 THE BRITISH NATURALIST. [j 



THE PTEROPHORINA OF BRITAIN. 



BY J. W. TUTT, F.E.S. 



(Contimted from Vol. III., Old Series, p. 2jj.) 



Aciptilia baliodactyla. — This and the preceding species tetradactyla 

 are very closely allied, and tetradactyla appears at least in one respect 

 to form a close connecting link with such Leioptili as microdactyla, in 

 both of which species there is a distinct sexual dimorphic tendency 

 strongly evident, although in baliodactyla the tendency in this direction 

 is not at all strongly marked. 



Synonymy — Baliodactyla, Zell., 'Isis,' (1841), 861; * Linn. Ent. Zeit./ 

 VI., 393 ; H.-S., 36, V., p. 384 ; Frey, 418. Tridactylus, Stphs., 4 111.,' 

 IV., 373 ; Wd. 1634. 



Imago — The anterior wings of baliodactyla are divided into two lobes, 

 both of which are very acute and the lower slightly falcate, by a fissure 

 extending half way to the base. The colour is of a pale ochreous ; the 

 costa, from the base to the point directly above the fissure being narrowly 

 fuscous ; the point of termination of this shade being sometimes sharply 

 defined and making a dark costal blotch, another similar linear costal mark 

 being found between this and the apex ; in some specimens these costal 

 marks are very inconspicuous, in others very distinct. What few 

 markings there are in baliodactyla correspond in position with the better 

 developed markings in spilodactyla. The moth has altogether a very clean 

 appearance. The hind wings are of an ochreous tint, sometimes with a 

 slight coppery hue and divided into three plumules. Stainton's diagnosis 

 is as follows: — " 11"' — . F.-w. yellowish white; a blackish line 

 along the costa from near the base to beyond the middle, and a dark 

 brown blotch in the costal fringes. VII." (" Manual," II., p. 444). 



Larva — The larva of this species is thus described by Mr. South : — 

 "Length seven lines, tapering towards the anal extremity. Head 

 smaller than second segment, yellowish-green ; a small black spot on 

 each cheek, and brown mandibles. Ground colour dingy green, seg- 

 mental divisions and dorsal line yellowish-green. Tubercles, two dorsal 

 rows (four on each side) whitish, with tufts of white hairs ; subdorsal 

 and spiracular rows, two warts on each segment, the anterior wart on 

 each segment in both series is the longest, and one hair of the fascicle 

 emitted therefrom is longer than the others. Prolegs and anal claspers 

 transparent yellowish-green. • Food, marjoram (Origanum vulgar e). 

 Eats the terminal leaves ; generally to be found at rest in the day-time 

 on a plant, the top of which the larva has caused to droop by biting into 

 the stem. Feeds in the evening. June " (" Entomologist," Vol. XVI., 



P- 2 5)- 



