254 Mr. G. F. HaTnpson on the 



XXXIV. — On Recent Contributions to the Classification of 

 the Lejndoptera hy Prof. J. II. Comstock * and Dr. T. A. 

 Chapman f. 



Pkof. Comstock's discovery of the method of uniting tlie fore 

 and hind wings in the Hepialidte and Micropterygidge by 

 means of what he terms a "jugum," and that the same 

 organ exists in the Trichoptera, is of the greatest interest to 

 entomologists. This jugum consists of a membranous lobe 

 from near the base of the underside of the fore wing, holding 

 the base of the costa of hind wing as in a vice, between it 

 and the inner margin of the fore wing. In most of the other 

 families of Lepidoptera the wings are united by the frenulum, 

 a strong bristle, single in the male, usually multiple in the 

 female, arising from the base of the costa of the hind wing 

 and articulating with the retinaculum on the underside of the 

 fore wing, which generally consists, in the male, of a mem- 

 branous bar or plate from below the costa or a fold of the costa 

 itself, in the female of a tuft of hair from the median nervure. 

 In many families and genera, however, the frenulum has 

 become aborted and an expansion of the costa of the hind 

 wing prevents the displacement of the wing. The frenulum 

 originally consisted of a tuft of hair, and retains its primitive 

 form in some female Cossidas and other lowly organized 

 forms, but in most moths has been developed into three 

 strong bristles in the female and a compound single bristle in 

 the male ; though in the Xoctuid genus StictojAera and in 

 the Phycitinge it is single in both sexes, in the latter — a sub- 

 family of the Pyralida". — the retinaculum, in both sexes, con- 

 sisting of a tuft of hair from the median nervure. 



That the Hepialidte and Micropterygida^ are widely sepa- 

 rated from all the other families of Lepidoptera has long been 

 recognized by reason of their having twelve veins to the hind 

 wing as in the fore wing, no other family having more than 

 eight ; but that they are closely related to each other has 

 been constantly denied, owing to the great difference in form 

 and size and the existence of highly developed biting mouth- 

 parts in the Micropterygidge, whilst in the Hepialidaj the 

 proboscis and usually the palpi are wanting ; so that the 

 discovery of a specialized common structure in the jugum is 

 a fact of great importance. 



* J. H. Comstock, "Evolution aud Taxonomy," Wilder Quarter 

 Century Book, Ithaca, N, Y., 1893, pp. 37-113. 



t T. A. Chapman, Trans. Ent. Soc. 1893, p. 97, and 189-4, p. 335. 



