2 THE ENTOMOLOGIST S RECORD. 



each of these. This only occurs when the moth has been 

 disturbed in laying and begins afresh, and there will often be 

 40 or 50 and, with rumicis and veiiosa, 100 or more eggs laid 

 with perfect regularity. 



The characters of the eggs may be most easily compared if 

 shown in a tabular form : — 



The greater height of myriccB is due to its being a somewhat 

 larger Q.g% than the others and being more often laid singly. 

 Such a specimen was selected for measurement and showed a 

 greater height than could be found in them in an imbricated 

 mass. The heights are given as actually recorded, but my 

 impression is strong that the differences between the several 

 species in this respect is trifling or evanescent. 



It is curious that the number of ribs should vary as it does, 

 and especially that the difference should be so great in the 

 most allied species, menyanthidis and myriccs having respectively 

 66 and 50, and rumicis and venosa 54 and 44. This is quite 

 parallel to what obtains between psi and tvidcns, and probably 

 has some relation to the circumstance that, though these pairs 

 occupy the same areas and emerge at the same times (or 

 nearly so), hybridisation as to none of them has been recorded. 



DESCRIPTION OF PLATE VII. 



Fig. I nnd 2. — Egg of Viminia rumicis x 25 diam. 



Fig. 3. — ,, ,, venosa x 25 diam. 



Fig. 3a. — Sketch of group o^ venosa eggs shewing imlirication x 25 diam. 



Fig. 4. — Egg of Viminia amicoma X 24 diam. 



Fig. 4a. — ,, ,, ,, vertical section. 



Fig. 4b. — Sketch of imbricated group oi auricoma eggs X 25 diam 



Fig. 5. — Egg of Viminia myriccc X 21 diam. 



Fig. 5a. — ,, ,, ,, vertical section. 



Fig. 6. — ,, ,, menyanthidis x 22 diam. 



Fig. 6a. — Sketch of imbricated group o{ menyanthidis e:^gs x 17 diam. 



