55 



2. Varieties confined to one sex. — For example, Oolias Edusa 



var Helice. 



3. Varieties of accidental or solitary occurrence. 



4. Albinos and black varieties. These are, perliaps, monstrosities 



rather than varieties ; the albino depending on a deficiency, 

 the black variety on an excess of pigmentary matter. 

 Examples of the former are frequent and of the latter occur in 

 Hypercamfa dominula, Qidaria impluviata, Prays Gurtisellus, &c. 



5. Varieties in the time of appearance occur in the imago as in 



the larva state. 



This sketch vrould be yet incomplete without noticing two groups 

 of distinct species, which seem as it were, to mimic varieties. An 

 example of the first group is given by Acronycta Psi and A. Tridens ; 

 in these, as is well known, the perfect insects are exactly similar, while 

 the larvae are widely dififerent. Of the second group, Gidaria russata, 

 and G. immanata may be taken as examples ; here we have the typical 

 forms of the imago very different. But both species are liable to 

 variations, and these varieties are in some cases indistinguishable the 

 one from the other, seeming to run together. 



Though, doubtless, many omissions are made in this list, yet 

 enough has been said to show that, in these varieties, a large field for 

 thought and observation exists, much of which has never been worked 

 at as its interest demands. 



Spring Orove Terrace, Edghaston. 

 May ISth, 1864. 



NEW SPECIES OF BUTTERFLIES FROM GUATEMALA AND PANAMA, 

 BY HENET WALTER BATES, E.Z.S. 



(Continued from page 35). 



22. — MELIN^A IMITATA. 



Same size and shape as Melincea Messatis (Mechanitis id. Hewits. 

 Ex. Butt. Mech. f. 4) : in colours and markings almost identical with 

 Heliconius Telchmia (Doubled. & Hewits. Gen. Diurnal Lepid. pi. 14, 

 f. 4). Fore-wing black, with a very broad and oblique sub-basal orange- 

 tawny belt, commencing on the costa (of which it occupies the l)asal 

 ])ortion), becoming narrower posteriorly, and terminating very near the 



