424 REVISION OF FAMILY SATURNIID.E. 



pieces are, while retaining the chief features of the group, still strongly- 

 characteristic, and are best described by a reference to the figures. 

 Expands 3-4 inches. Hah. — United States, east of Eocky Mountains. 



A. angulifera Wlk., C. B. M. v., 1224, 1855 (Samia) ; Morris, Syn., 1862, 227 {Samia) ; 

 Pack. Pr. E. S. Ph., 1864, iii, 380 (Callosamia) ; Eiley, 4th Mo. Rept., 122, 

 note; Suppl. 55=promethea. 



Allied to promethea, of which it has been considered a variety. There 

 are, however, abundant characters separating them, an enumeration of 

 which will suffice for a description. The specimens known to me are 

 uniformly larger, the male and female are similar in wing form, and 

 the wings are more rounded than in promethea. The male, though 

 darker in color than the 9 , has essentially the same markings, and 

 is only a little smaller. The angular mark is much larger, more an- 

 gular, and more distinct in the male of this species than in that of its 

 ally. The maculatiou is essentially that of the 2 promethea, with the 

 colors less bright, and with a more luteous cast. In venation the two 

 species agree exactly. The supra anal plate is like that of promethea; 

 but the side pieces are very distinct, as a comparison of the figures will 

 show. No comparative descriptions of the larva have yet been made 

 to my knowledge, and the food plants seem to be as in promethea. 



A. Columbia Smith, Pr. B. S. N. H., ix, p. 343, Mcar., 1863 (Samia) ; Pack., Pr. E. S. Ph., 

 iii, 1864, 380 (Samia) ; Wlk., SuppL, v, 1934 (1866) ; Hageu, Buff. Bull., ii, 201, 

 1875; Strk.,Lep., i, 103, pi. xii, fig. 3^; Beth. Cau. Eut., i, 44 (46); Bowles, 

 Can. Eat., iii, 201, f. 37 (larva); Brodie, Pap., ii, 79 (food-plants) ; Strk., Pr. 

 Dav. Ac. N. Sc, ii, 277, 1878 (larva). 



This species has been sui)posed by some to be merely a local variety 

 of eecropia, and it has been compared with that species, from which it 

 seems to me very clearly distinct. I am not, however, able to separate it 

 very satisfactorily from glover i. The venation is the same, the genitalia 

 are the same, and but for some slight differences in maculatiou which 

 are not constant and the fact that the S antennae are not so dispropor- 

 tionate, the entire insect seems the same. In size it is uniformly some- 

 what smaller, but I am at a loss to find any other sharp defining feature. 

 I believe it to be another of those cases where a western form has found 

 its way along some isothermal or other natural line, to the northeast, 

 and has become somewhat modified by the changed conditions. The 

 home of this species is Maine and Canada, and Maine especially, offers 

 a number ot jiarallel cases where typically western forms of IsToctuidse 

 there occur in a slightly modified form. The larvae of both Columbia 

 and gloveri have been described, and Mr. Strecker has pointed out the 

 differences, which consist in the color of the tubercles on the anterior 

 segments; that of columMa is known to vary (see Ent. Am., ii, 18), and 

 there seems little reason for doubt that the two forms are identical. I 

 have seen large series of both columMa and gloveri, and yet hesitate to 

 refer them as synonymous until new regions can be heard from, because 

 I have not been able to fill the gap in the size of specimens, and also 



