92 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 57. 



brown; mandibles brown; tips and attacbments of mandibles and 

 mandibular attachments of epicranium black; setae of post mentum, 

 broad and flattened; ocellar pigment black, individual under each 

 ocellus. In earlier stage larvae the head and all chitinized areas 

 about tubercles are dark smoky fuscous, being quite conspicious. 



Pupa. — Light brown, slightly darker at caudal and cephalic ends; 

 spines of last three abdominal segments dark brov/n; attachments of 

 forewings forming a slightly raised shoulder, blackish brown; spira- 

 cles black, that on 8th abdominal segment only slightly larger than 

 the others; metathoracic legs extending as far beyond mesothoracic 

 as mesothoracic legs extend beyond the extremeties of wings; pro- 

 thoracic legs extending a trifle beyond tips of antennae; maxillae 

 only a little over half the length of antennae; male 16 mm., female 

 19 mm. long, 4.5 mm. wide. 



The Pyraloid origin of this genus is distinctly shown in the large 

 pilifers of the pupa and in several larval characters. Abdominal 

 setae IV and V, it is true, are rather remote which would indicate a 

 more primitive form; but in the other Thyridids I have seen they 

 are closely approximate. Again in Hexeris as well as in Thyns, 

 Dysodia, and TJiyrido'pyralis the prespiracular shield of the prothorax 

 bears only two setae {IV and F), a distinctly Pyraloid character. 

 Fracker's statement* that the Kappa (Prespiracular) group of the 

 prothorax is trisetose in Thyridide is obviously an error in ob- 

 servation. The blown larvae of Dysodia oculatana in the Uni- 

 ted States National Museum which he examined are plainly bise- 

 tose. The position of alpha (/) on the 9th abdominal segment 

 which he also uses is not a reliable family character, in the 

 Pyraloidea at least. As we now classify the groups it is of some- 

 what less than subfamily value. In Dysodia it is higher than beta 

 (IF) while in Hexeris it is considerably below it. On larval and pupal 

 characters, therefore, we will be compelled to consider the Thyridinaej 

 as a sub-family of the Pyrahdae closely related to both the Galleriinat 

 and Phycitinae. 



EXPLANATION OF PLATES. 



Terms used in description of male genital organs. — (Adopted ■vritli slight modifica- 

 tions from T. N. Pierce's Genitalia of the British Noctuidae, Liverpool, 1909; Geni- 

 talia of British Geometridae, 1914.) 



Ae Aedoeagus (chitinous sheath of penis). 

 Agl Anal angle of harpe. 



Cn Cornuti (spines on penis proper, seen through wall of aedoeagus). 

 Cs Cucullus of harpe. 



Fp Caudo-lateral projections from tegumen. 

 Gn Gnathos. 



Hp Harpe (Sensu'J. B. Smith and Pierce; Noctuidae="'valYa," Pierce: Geome- 

 tridae). 



1 The Classification of Lcpidopterous Larvae, 111. Bio. Monographs, vol. 2, no. 1, July, 1915, pp. 74-75. 



