NOTES ON COLLECTING. 95 
whilst generally applicable, there are a good proportion of specimens of 
both species that present, not the markings here predicated of them, 
but those of the other species.” 
At the same time Dr. Chapman read his notes he showed speci- 
mens obtained from various collections, viz.:—(1) Dr. Mason’s. 
Several appeared to him wrongly determined and on examination were 
proved so in each case. (2) Mrs. Bazett’s. The series of tridens. 
Seven out of eight appeared to him to be ps7, and this opinion was 
verified on examination. (8) C. G. Barrett's. On examination of 
these it was found that two specimens of psi were placed with tridens 
—three specimens of tridens with psi. 
In conversation with Dr. Chapman a few days ago he said that 
males with dark hindwings are always psi, while the males with white 
hindwings are sure to be ¢ridens. Also that the bidens form of pst 
never occurs in tridens, nor does the pink form of tridens ever occur 
in pst. 
As a result to differentiate the imagines in words is practically im- 
possible. The only reliable differences are biological and structural. 
Pierce, in 1909, Gen. Brit. Noct,, gives the clasper of tridens as trifur- 
cate, while that of psi is bifurcate ; and an examination of the figures 
on the plate leave no hesitation in one’s mind as to the definite 
difference of the two, it is not a difference of degree. The best and 
only satisfactory way, of course, is to obtain the larve and breed the 
species, which are easily separable in that stage. With Dr. Chapman’s. 
paper as published in the Trans. City Lond. Ent. Soc. is a plate show- 
ing photographs of the clasps of the two species, where the differences. 
are shown very well indeed.—H.J.T. [It is a curious coincidence 
that the name tridens might have referred to the clasps rather than 
to the wing-markines, three processes in tridens, two in psi. Even 
the pupa presents a similar coincidence.—T.A.C. ] 
JOTES ON COLLECTING, Etc. 
PHIGALIA PEDARIA (PILOSARIA) FROM SHERWOOD Forsust.—I have just 
had sent to me by Mr. Daws, of Mansfield, some twenty examples of 
Phigalia pedaria (pilosarvia) as a sample of the forms that have been 
taken in Sherwood Forest this spring. There are four main types of 
ground and general colouration and three subsidiary ones. 
1. Six specimens in which there is a greenish coloration, in one of 
which the green is slightly tinged with yellow in places. The costal 
clouds of these specimens are well marked, but the lines are not well 
defined on the five former examples. The one partially tinged with 
yellow is well marked, in some of the markings black prevails, in others. 
brown. There is good contrast between ground and markings, so that 
the specimen is a very pretty one. 
2. Five specimens are of the soft grey general coloration, four of 
them being light in appearance and very much dusted with black, not 
brown. The costal clouds are well developed in all five specimens. 
The lines in the four are black, fairly well defined although diffuse. 
In the fifth specimen the forewing is devoid of most markings except 
the well marked costal clouds, and the grey is somewhat darker. The 
hindwings have the central transverse irregular band perfect and. 
prominent, but the submarginal in the fifth is not nearly so perfect. 
