of certain species of Willow. — Part 2nd. 241 



VII. In common with preceding authors, I have described the 

 veins in the Tenthredinidous wing as black, brown-black, &c., without 

 taking any notice of the white "bulla?,'' which exist upon the veins 

 throughout this family as I have shown them to exist throughout leh- 

 neumonidse.* As is also the case in Ichneumonidse, we find here in 

 each genus peculiar modifications of the typical system of bulla). For 

 example, in Hylotoma the 1st submarginal cross-vein has one bulla 

 much behind the middle; the 2nd submarginal cross-vein has two bul- 

 lae, either confluent (7/. scutellata Say) or separated by a more or less 

 considerable space; (II. calcanea Say, If. dulciaria Say, IJ. cocctnea ? 

 Fabr. and M. McLeayi Leach;) the 3rd submarginal cross-vein has 

 two bullae, placed one of them well forwards and the other well back- 

 wards, aud separated by a wide space; and the 1st recurrent vein has 

 one bulla placed at its extreme anterior end, and so as to extend on to 

 and beyond the vein in front of it, besides the two universal bulla? 

 which I have lettered F and G in Ichneumon — making in all eight 

 bulla?. Contrary to the general rule, there are in this genus absolute- 

 ly no bulla? whatever on the 2nd recurrent vein. The genus Tenthre- 

 do, (including as sub-genera, in accordance with Hartig's opinion. 

 Strongy/ogaster, Taxonus, AllantuS\ Jfacrophya, Pacltyprotuxis and 

 Selandria) has the same eight bulla? as Hylutoma, except that the bul- 

 la on the 1st submarginal cross-vein (iV, see below, fig. 1) is placed in the 

 middle, instead of much behind the middle, and except also that the 

 two bulla?, located respectively on the 2nd and 3rd submarginal cross- 

 veins, are always widely confluent so as to cover nearly the whole vein; 

 and in addition it possesses a bulla a little behiud the middle of the 

 marginal cross-vein (M.) and two others, which are quite or nearly con- 

 fluent, a little before the middle of the 2nd recurrent vein, correspond- 

 in"; to those which I have lettered C and D in Ichneumon — making: 

 in all eleven bulla?. In the genus Emphytus, on the other hand, where 

 the 1st submarginal cross-vein is generically absent, the bulla on that 

 vein is necessarily absent; aud as the bullar system is otherwise the 

 same as in Tcnthrcdo, this genus has consequently ten bulla?. Finally, 

 in the genus Dolerus (including Dosytheus), as the 2nd submarginal 

 cross-vein is generically absent; the two bulla? found there in Tenthre- 

 do are necessarily absent; and as the bullar system is otherwise the 



* Pror. etc. V, pp. 209 — 215. Since that Paper was written, I have examined 

 numerous European species belonging to many different genera of Ichncumoni- 

 dce, and ascertained that the bulke follow precisely the same laws in exotic as 

 in indigenous species. 



riiOCEEDI.NGS BUT. S0C. PHILAB. DECEMBER, 1866. 



