2 BRITISH LEPIDOPTERA. 



or less strongly rounded. Neuration : discoidal cell of all wings closed ; the " closing- 

 nervure " of the forewings broken in the middle, that of the hindwings broken near 

 the front angle. Forewings with I2nervures : 2 — 5 separately out of the middle cell, 

 6—8 either all free out of the front angle of the middle cell or 6 and 7 (decolorata, 

 staudingeri) with very short stalk, or 8 out of 9 and 10 (salomonis). 9 and 10 with a 

 common stalk, which is always much (3 to 5 times) shorter than the free part of the 

 nervures, 11 free out of the costa, 2 — 9 run into the outer margin. Hindwings with 8 

 nervures : 2 — 5 free out of the middle cell, 6 out of the front angle of the cell, 7 arising 

 before the middle of the upper margin of the cell ; 8 approaches 7 for some distance 

 behind the commencement of the latter, and anastomoses with it either a longer or 

 shorter distance, or is joined to it by a short obliquely-placed transverse nervure 

 The basal cell is consequently moderately large, and extends almost as far outwards 

 as the front angle of the middle cell ; from it, no distinct supplementary nervures run 

 towards the costa. Antennas, $ , strongly pectinated; ? , with short pectinations or 

 nearly simple, with scarcely noticeable pyramidal teeth (staudingeri). Abdomen uni- 

 formly-haired without anal wool. Wings in staudingeri, aborted, very short, in the 

 rest of the species longer in the ? than in the g . Flies June to August. Larva : 

 The full-grown larva densely and uniformly-haired ; the hairs consist both of longer 

 erect ones and of shorter ones bent in different directions. The hairs cover the whole 

 upper side, and leave only the front and hind margin of each segment free ; there, on 

 this account, the colour and markings of the skin are very distinct ; head varying from 

 yellow-brown to brown, with dark markings or blue-grey with light markings. 

 Pupa : Thin-shelled, yellow-brown in colour, without anal hooks, in a firm and thick 

 parchment -like cocoon, which is without an " athemloch " or " breath-hole." 



There are, in this subfamily, two well-defined tribes : (1) The 

 Pachygastifidi, including the species so generally known as the Lasio- 

 campids (sens, strict.) and divisible into three genera — Lasiocampa (type 

 querciis), Aurivillia* (type decoloratd), Pachy gastrin, (type trifolii). 

 (2) The Lambessidi, with only one genus — Lambessa (type staudingeri). 

 These subdivisions are well shown in the tabulation proposed by Auri- 

 villius {Iris, vii., pp. 150 — 151), which reads as follows : 



A. Female with developed wings and shortly-pectinated antenna?. 



a. Forehead and front tibia? unarmed ; front tibia? longer than the first tarsal 



joint — quercus, grandis, serrula. 



b. Forehead with a corneous protuberance. 



1. Front tibia? at the tip unarmed, as long as first tarsal joint — decolorata, 



datini, davidis. 



2. Front tibia? at the tip armed with a distinct spine, shorter (or at least not 



longer) than the first tarsal joint — trifolii, josua, everstnanni, nana, 

 concolor. 



B. Female with undeveloped wings, and with nearly simple (unpectinated) antennae; 



forehead and front tibia? armed — staudingeri. 



Of these groups we have in Britain representatives of A, sect, a — 

 quercus, and A, sect, b — trifolii. The former species is the type of the 

 genus lasiocampa, the second of the genus Pachygastria. Christoph 

 gives (Stett. Ent. Zcit., xxviii., pp. 240 — 242) a note on Pachygastria 

 eversmanni, in which he states that it is a distinct species, and that he 

 inclines to believe ratamae and terreni to be varieties of this rather than 

 of P. trifolii, while he also is inclined to consider codes a distinct 

 species. 



Gynandromorphism must be exceedingly prevalent in this sub- 

 family, if the known examples of Pachygastria trifolii and Lasiocampa 

 (jucrcus may be considered as offering any basis for generalisation. 

 Schultz alone records {/Hits. /.cits, fiir Ent., ii., p. 494, and hi., p. 311) 

 no less than 31 gynandromorphous examples, viz., Pachygastria trifolii 5, 



* Diagnosed by Aurivillius as : " Forehead with a corneous protuberance. Front 



tibia- at tin- tip unarmed, as long as first tarsal joint." Then- is. we know, a gen us 

 Aurivilliana, Dist., but we consider this name sufficiently distinct. 



