( 20) 
with which it is here associated has no continuous dark mark- 
ing, except at the apex of the fore-wing. Experience, however, 
leads me to think that although a border of black spots on a 
white or pale-coloured wing—the arrangement so commonly 
seen in Mylothris but obsolescent in this particular form—is 
a conspicuous feature, a uniform dark border (as in Belenois 
severina, Cram., 9) is often unnoticeable during flight; the 
chief effect of sucha border being to diminish the apparent size 
of its possessor, and sometimes (if the internal bounding line 
is irregular) to convey in addition the impression of a worn or 
ragged edge tothe wings. There is reason therefore to suppose 
that the resemblance between these two forms is quite close 
enough to be effective, 
“ Tt may, in conclusion, be remarked that the present case is 
in some respects analogous with that of Papilio dardanus. In 
both we have a series of females, differing widely from the 
male and from each other, and each bearing a resemblance to 
a protected form belonging to another group. The differences 
in Z. argia, though similar in kind, are far less striking in 
degree than those shown by P. dardanus; this corresponds 
with the greater family resemblance between the models of 
the Leuceronia as compared with those of the Papilio.” 
[xxxiii 
Mr. R. SHELFoRD read the following note on 
“ A Case oF Homamortic VARIATION IN A COCKROACH.” 
Homeeosis has been defined as “‘theassumption by one member 
Left maxilla. Right maxilla. Right mandible. 
of a Meristic series, of the form or characters proper to other 
