URBICOLA COMMA. 179 



bases. The cranium (?) is quite without hairs of this sort. Its sculpture 

 is made up of circular dark marks (pits) with raised dark margins, the 

 centre paler. These marks are from 0'04mm. to OOBmm. in diameter 

 and vary somewhat from strict circles, the areas between them are 

 invaded a little by their outward slopes, but may be described as an 

 intermediate plain, with from half to twice the diameter separating the 

 circles. (These circles are the simplest form of head sculpture in 

 similar larvae, which becomes more complicated as they get more 

 crowded together and form waved and other raised ridges.) These 

 rings are not hairs, the true hairs are extremely minute, and occur in 

 the smooth plain between the rings, their numbers are almost identical. 

 The eye-spots are the usual five in a curve and one central one. The 

 antenna, rising from a chitinous ring at base, has two joints, the first 

 about 0-15mm., and the second 02mm., long, the latter carries a long 

 hair (nearly 1-Omm.), and also a minute joint, which again has two 

 very minute papilla?, one with a minute hair. The jaws are large, 

 somewhat cubical, boxes; the cutting margin is a smooth curve, over 

 1-OOmm. long, quite without teeth. There are more complicated and 

 jointed maxillary palpi, but the details of these and the labium are not 

 made out ; the labrum is about 0-7mm. across, and has a central notch 

 with the usual rounded lappets on either side. The true legs are black, 

 with a rather short straight claw ; the basal joints have many short 

 strong bristles, as has also the basal area, which has a transverse 

 dark plate strongest for the first, weakest for the third, pair. 

 [Described from a cast larval skin ; from a larva which was found at 

 Albarracin in August, 1901. The larval skin was covered with the 

 material from the larval pockets under the 7th and 8th abdominal 

 segments ; so great was the quantity that I thought I must have left 

 the box somewhere, where the larval-skin and pupa-case had been 

 destroyed by mould. Closer examination, however, showed at once 

 that the material with which they were covered was the white, glistening, 

 fibrous, asbestos-like powder excreted from the larva, and the way in 

 which the larval skin had the larger share, doubtless made more 

 obvious by its being shrivelled up, showed that the distribution of the 

 powder was made whilst the larva was still actively spinning. The 

 material instantly dissolved off the larval-skin when benzole was 

 applied to it, as a necessary preliminary to endeavouring to soak the skin 

 in order to make some examination of it. I was not very suceessful in 

 unravelling the shrunken skin, but did so sufficiently to be able to note 

 the few structural points detailed above (Chapman).] 30mm. in 

 length when fullgrown. Head heart-shaped, glossy-black, with a pale 

 brown patch on each hemisphere ; below is a similarly coloured upturned- 

 A which limits the triangular forehead ; in proportion to the larva, the 

 head is rather large and divided by a deep indentation extending from 

 the small prothorax, as in all other Urbicolid larvae. The prothorax 

 carries dorsally, on the hinder half, a narrow, horny, black ring, which 

 extends to the large black prothoracic spiracles. The colour of the 

 body is a dirty greenish-grey, or black-grey, with a tinge of green. The 

 true legs and spiracles are glossy black (Staudinger) . See also antea, p. 1 7 1 . 



Foodplants. — Aira caespitosa (Frohawk), Festuca ovina (Wocke), 

 Poa, Triticum, Holcus (Riihl). [Also recorded as feeding on Coronilla 

 varia (Schiffermuller, etc.), Ornithopus perpusillus, Lotus comiculatus, 

 etc. (Merrin).] 



Puparium. — In nature, the puparia are spun on the ground, and 



