114 Annals Entomological Society of America [Vol. Ill, 



Family Lacosomiuak. 



Prolegs with a complete circle of hooks, alternately of two lengths ; 

 body with four setae representing vii (the fourth one being probably 

 vib) but otherwise without suljprimaries; iv and v approximate below 

 the spiracle, and on a level; all the setae clubbed; head Macro in its 

 type of appearance; higher than wide; front rather high and extend- 

 ing half way to vertex; anal legs with a practically complete circle of 

 hooks; labium with high narrow mentum, and rather small submenta, 

 not meeting. 



Exami)le Lacosoma chiridota, lialfgrown. Figs. 93. 94 and 95 



Thaumetopoeidae. 



Secondary hair on epicrania, front, adfrontals, mandibles, maxil- 

 lae and labium, bui not on clypeus or labrum. Front small; setae 

 moderate, the punctures trisecting the space between the primaries; 

 as wide as high, adfrontals narrow; labrum with a very shallow cleft. 

 Hi and iv distant, vi a very short distance from the margin. Prolegs 

 with hooks all of the same length, in a' single band, the anal prolegs 

 with the same numlier of hooks (18) as the ventrals. Body with 

 tufted hair, the tufts ii. Hi, iv, and vi, as well as vii and viii of the 

 legless segments, being distinct, the secondary hair is in two transverse 

 bands. Tuft i is of short dense hair, making the caterpillar look like 

 a Lymantriid. There arc no evcrsible glands. True legs with very 

 deeply and curiously cleft claws. The family is not American. 



These characters suggest very strongly the Lymantriidae, especially 

 Euproctis, without allowing one to deny that they may be due to 

 divergence from a more primitive Notodontan origin. Staudinger and 

 Rebel place it between the two families, which come together in their 

 arrangement. It is usually considered Notodontid. 



Exanii)li' Thaumetopoea (of ICurojie). I'i.U'^ '■""> and 97. 



Lymantuiidae. 



With secondary hair on epicrania, adfrontals, maxilla? and labium, 

 and sometimes on front, none on labrum, mandibles, etc.; front rather 

 large, somewhat higher than wide, the punctures close together, the 

 setae, when not obscured by secondaries, very high up and far apart ; 

 labrum quite variable; maxillae and labium much as in the Noctuidae 

 in form. Prolegs with a single l)and of hooks of a single length, the 

 ventrals and arials equal. Body with tufted, but no secondary hair; 

 wart i quite variable and furnishing generic characters, viii somewhat 

 diffuse, as if there wore a little secondary hair associated with it. 

 Claws of true legs moderately cleft as in most Lepidoptera (similar to 

 Fig. 101). Dorsal glands on Gth and 7th abdominal .segments. 



1 . Labrum more deeply notched, one third its height or more, seta 

 vi not on the margin, adfrontals enlarged at the top, with a tuft 

 of secondary sets; front and u])per part of epicrania without second- 

 aries. 



'2. Labrum cleft alK)ul half its height, seta- t and ii far out of line 

 with each other; hodv with tufts i small, and ii moderate, both normal. 

 Kxamjile Porthetria dispar. 



