122 



TWENTY-SIXTH REPORT ON THE /STATE 



FIG. 4. 



The larva of Alypia octomaculata is marked on each segment with 

 eight black bands (counting the two which border the broad central 

 FlG 3 - orange band), as shown in a of Fig. 3, 



and more distinctly in the enlarged 

 view of one of the segments at b from 

 the black dots long white hairs are given 

 out (represented too short in the figure), 

 and below the stigmata, on segments 

 four to nine, is a row of white spots, 

 with a large white spot extending over 

 the incisure of the tenth and eleventh 

 segments. At <?, a view is given of the 

 imago of this species. 



The larvse of Eudryas grata and of E. unio have six black bands 



and a central orange one on each of the 

 principal segments; they are without 

 the white lateral patches, and have a 

 prominent hump on the eleventh seg- 

 ment. A representation of the imago 

 of E. grata is given in Fig. 4, for com- 

 parison with octomaculata and epimenis, 

 and to illustrate the fact well known to those who have studied the 

 larvse of our Lepidoptera, that very dissimilar moths are frequently 

 produced from larvse closely resembling one another.* 



I regret my inability to give, at the present, the differential fea- 

 tures of grata and unio. At maturity they differ in size, unio being 

 invariably the smaller. In markings they resemble one another so 

 closely, that Mr. Biley, after a critical comparison of examples of 

 unio which I had sent to him, with some examples of grata in his 

 possession (probably alcoholic), writes me, that he finds the two spe- 

 cies absolutely indistinguishable. 



While specific differences may not be detected in alcoholic indi- 

 viduals, there is scarcely any doubt but that sufficient characters for 

 their identification could be obtained from a comparison of the colors 

 of the living forms. Having lately seen a large number of grata 

 larvae (at Portland, Me., in August, 1873), I may safely assert that 

 the two species differ materially in their general aspect. While 

 unable to state from recollection what these differentia are, I believe 

 that unio will prove to be characterized by more prominently marked 



* The figures illustrating this article are from the excellent drawings of Mr. C. V. 

 Riley. 



