232 ENTOMOLOGICAL NEWS [May, '17 



Pupal Diiferences in Megathymus (Lep.). 



Mr. J. G. Bonniwell, who has collected the pupae of Megathymus 

 yuccac and cofaqui, has recently sent me specimens of the pupal 

 tubes of both species and also the empty pupal shells. There is a 

 marked difference in the silk tubes from which the images emerged, 

 both in size and in color. When cut open and measured across, that 

 of yuccae is 45 mm., and that of cofaqxii 34 mm. The outer sides of 

 these pouches, tubes or nests are covered by what appears to be the 

 plant fibre chewed up by the larvae and is rather fine and disintegrated. 



In the case of M. yuccae it is of dark gray color and in M. 

 cofaqui it is yellowish brown. In these two specimens the difference 

 in color is marked. The two pupae he sent me also differ in size, 

 that of yuccae being 45 mm. long, that of cofaqui 40 mm. long, and 

 the former is more robust. 



Dr. C. V. Riley in his account of the pupa of yuccac describes it 

 as ending in a slightly decurving flap. In the two specimens ex- 

 amined this is approximately twice as wide in yuccae as in cofaqui. 

 There are probably differential pupal characters in addition, but from 

 only one specimen of each I could not be sure whether they were dif- 

 ferential or only individual, or possibly sexual. 



Some time ago Dr. D. M. Castle gave me a yucca plant that had 

 a borer in it and I was able to rear it to the adult stage and it 

 proved to be Megathymus yuccae. The silken pupal tube extended five 

 and one half inches above the ground and the upper end was covered 

 with a certain amount of what appeared to be frass. The whole plant, 

 including the leaves, was fourteen inches high. The type of cofaqui 

 is a female and the male was recently described in the Bull. Am. Mus. 

 Nat. Hist., 1917, XXXVII, 36. We have had both sexes for many 

 years. I described Megathymus stephensi, a Californian species, as a 

 variety of neumocgeni but I now consider it a distinct species, and I 

 think an examination of the genitalia would prove this to be correct. 



The genus is an interesting one and the insects far more plentiful in 

 nature than one would think from finding the imagos, which have 

 always been rare in collections. — Henry Skinner. 



Synonymic Notes on North American Lepidoptera. 

 Thanaos callidus Grinnell. 



In our Contributions (Vol. Ill, No. 2, pp. 122-3), we suggested that 

 the male and female types of this species were not conspecific, that the 

 female type, after which seemingly most of the identifications had 

 been made, was probably the same species as lacustra Wright, but that 

 the male type, which automatically would hold the name, was probably 

 a form close to persius. Since then, through the kindness of Mr. 

 Fordyce Grinnell, we have examined the types of callidus as well as 

 the single male type of pernigra and find that our surmise was correct; 



