PACHYGASTRIA TRIFOLII. 9 



in der Mitte der Vorderfliigel ist hellweiss, und braun eingefasst. Die 

 Binde ist ausgeschweift, und von gleicher Breite, zur Seite dunkelroth- 

 lich grau eingefasst. Sie ist von bleicher Farb. Das Mannchen ist von 

 dunkleren Colorit, und hat blasse starkgefiederte Antennen mit einem 

 weissen Stiel (Esper, Schmett. Eur., pp. 87, 88). 



Imago. — 43'74 mm. — 67*5 mm. Anterior wings yellow, reddish- 

 grey, or reddish-brown ; a white, dark-edged discal spot ; a pale 

 curved transverse line between this spot and the hind margin ; a more 

 obscure transverse line between the discal spot and the base ; some- 

 times a pale basal patch ; outer area sometimes irrorated with pale 

 scales. Posterior wings unicolorous yellow, reddish-grey, or reddish- 

 brown, sometimes with faint transverse shade. Head and thorax of 

 the same colour as forewings, the abdomen as the hindwings. 



Sexual dimorphism. — The females are usually much larger than 

 the males, the forewings more extended and rounded at the apex, and 

 somewhat less densely scaled. A number of males give measurements 

 extending from 4374 mm. — 50 mm., a number of females from 46 mm. 

 — 67*5 mm. The males have strongly pectinated antennae, whilst those 

 of the females are comparatively simple, and the general build of the 

 sexes suggests the actual difference of habit — the quick zig-zagging 

 flight of the males, the steadier, heavier flight of the females. The 

 $ antennae are about 12 mm. in length, the plumules about 2 mm. ; 

 there are about 65 joints, the plumules hang down (in lop-eared fashion), 

 side by side. The antenna is like that of L. quercus in having opposite 

 plumules of equal length, and in having the strong terminal spike quite 

 on the front of the terminal (slight) bulb, and in pointing forwards 

 parallel with the antennal stem ; about 7 2 transverse rows of hairs to a 

 plumule, those of the two sides not always opposite. The terminal 

 spike is very thick and strong, and the notch half-way up is barely 

 indicated; no trace of scaling on pectinations. The 2 antennae are 1 o 

 mm. in length, of about 60 joints, scaling irregular as in $ , plumules 

 about '3 mm. in length, slightly clubbed, have two end bristles, and the 

 thick spike, which is shorter than the bristles and much thicker, as in the 

 c? , arises not from extreme end, but from front of spike ; it is, however, 

 parallel with plumule and not with shaft of antenna as is that of the $ . 

 The plumules are clothed on almost all aspects with very fine short 

 hairs (Chapman). The colour of the wings is not usually strikingly 

 different in the sexes (although in both it is exceedingly variable), but 

 the transverse lines of the forewings are usually much more distinctly 

 marked in the males than in the females. The relative proportion 

 of males and females emerging from a number of pupae in the 

 possession of Standfuss is recorded as follows : 1882 — 29 $ s and 

 25 2 s, 1893 — 114 J s and 106 $ 5 = 143 $ s and 131 ? s. 



Gynandromorphism. — The following are the only records of 

 gynandromorphic examples of this species that have occurred to us : 



a. 3 left, ? right, completely gynandromorphous. The left ( 3 ) side shows the 

 colouring of the var. medicaginis, the right ( $ ) that of trifolii ; the left palp more 

 strongly developed and clothed with hairs ; the left forewing shorter ; on left side of 

 abdomen an anal tuft. The entire underside of the 3 wings yellowish, on the other 

 side, on the contrary, only the base is tinged with yellow. Bred in Zara. In 

 Macchie's coll. (Rogenhofer, Verh. z.-b. Ges. fllen., viii., p. 245). 



j3. 3 right, ? left. Abdomen like the ? but more slender, with extremely 

 accurate trace of the partition concerning the sexual parts. Of the form known as 

 var. medicaginis. In Berlin museum ; from Berg's coll. (K_lug, Verh., p. 367. 

 Jahrb., p. 255, &c). 



