NOTES ON PHEAGMATOBIA FULIGINOSA. 177 



moth laying on average some 60 eggs per day. Some further support 

 to this view is perhaps aftbrderl by the analogy with the'ova of Spilosoma 

 niendica, which Mr. Tutt forwarded at the same time. These did not 

 show any large composite patches, the numbers in each patch being 

 comparatively regular, only ranging from 34 to 52 in five patches, con- 

 taining some 200 to 220 eggs. In shape the eggs form as nearly as 

 possible f of a sphere, possibly they are, when first laid, quite 

 spherical, but become flattened at base while still soft, and the slight 

 h'regularities of surface which occur are probably due to stresses at 

 laying and during development. 



Ovum. — The horizontal diameter is between -Gmm. and •7mm., 

 generally nearer to the latter ; the vertical axis is, at a guess, 'Smm. 

 to 'Gmm., but it is difficult to gauge exactly, owing to the base being 

 depressed centrally, and consequently the vertical diameter is con- 

 siderably less than appearances Avould warrant. The surface is slightly 

 reticulated with a cellular pattern, but not sufficiently to deaden the 

 shining and pearly iridescence of the egg. The micro pyle is not very 

 specially differentiated from the surrounding surface, but owing to the 

 way in which the cellwalls run into the centre it is somewhat sugges- 

 tive of a lunar crater. 



Lakva. — Itit instai : In their 1st instar, after a short period of 

 growth, the larva* are quite normal Spilosomas in shape, with promi- 

 nent segments and deeply-cut incisions. No subsegments are apparent ; 

 the skin is covered with a coat of very minute spicules ; the tubercular 

 plates at base of primary setae are very large ; the sette or hairs are mostly 

 very long, stout, and thorny. The head, scutellum on prothorax, 

 anal plate and tubercular plates are pale brown, the general skin- 

 surface pale green. Tubercles : The dorsal tubercles on meso- and 

 metathorax bear two black hairs, probably i and ii conjoined ; iii 

 on all segments (mesothorax to 8th abdominal) bears two hairs. On 

 the abdominal segments i is small, and bears a very small, pale hair, 

 and is noticeably the inner ; ii, the outer, is very large, and bears a 

 very large and long dark hair. The lateral tubercles are not at all 

 easy to homologise ; iii is large and bears, as previously noted, two 

 long hairs on segments from 2nd thoracic to 8th abdominal. The 

 spiracles are small but distinct, with brown chitinous rims, and set 

 rather anteriorly on the segments ; the prothoracic is somewhat, 

 and the 8th abdominal much, larger than the others. On the meso- 

 and metathorax, beneath iii, and rather posterior to it, is a small 

 plate bearing a minute slender hair (? iv) ; below this, and slightly 

 anterior to it, is a large plate bearing a single long hair (? v), and 

 below this again is another large plate bearing two hairs." On the 

 abdominal segments, immediately beneath, and slightly posterior to 



* I am by no means certain as yet as to the exact homology of the thoracic 

 tubercles in this and the allied species. In larvae of Nenieophilu plant acjinit^ there is 

 another exceedingly minute tubercle and hair behind the large single-haired 

 tubercle below iii (? vi), and this is observable on the larva of Phrcuiinatohia 

 Uiliginoaa in later stages. (I have traced it on one larva in 2nd or .^rd instar, and 

 it is generally present in 4th or 5th stadium). According to Dyar's arrangement, 

 taking his figure of C'os.su.s co.s.sifs as a type, the meso- and metathoracic setae would 

 be upper dorsal plate bearing two hairs i and i(/, the plate beneath it, or sub- 

 dorsal or upper lateral area also bearing two hairs, ii and iia, and I presume the 

 strong hair and weak one above it would be iii and iii«, and the lower double- 

 haired plate be iv and v. 



