8 Mr. W. J. Kaye on 
space between the wings. In the specimens of the same 
species from Caracas the white spots at the base of the 
abdomen are very greatly reduced, and in one 9 hardly 
traceable at all. In 8. Brazil, at Castro in Parana, I found 
M. lades (= leucostigma) commonly, yet wasps of the genus 
Salius did not appear to be present. This was in March and 
early April. But Mr. E. Dukinfield Jones, who resided 
for many years at Castro, informs me that these fossors are 
quite common at different times of the year, only they 
usually occur but singly. 
Figs. 10 and 10a represent a most interesting case of 
mimicry from the Potaro River in British Guiana. Fig. 
10 is of the Syntomid moth, Sphecosoma testacea, and 
fig. 10a is of a small Pompilid or fossorial wasp, Batazonus 
polistoides. Neither of these species I have seen alive. 
Mr. C. B. Roberts, who collected for some years for me after 
I left the Potaro district, sent the wasp as a Syntomid moth 
along with several of the Sphecosoma testacea and with a 
still greater number of a closely allied species (but not 
figured on the plate) Sphecosoma anqustatum. Although 
the latter is considerably the commoner species, Sphecosoma 
testacea is more like the wasp as it shows the darkening of 
the costal area, which is a character agreeing with the wasp, 
while the commoner S. angustatwm does not exhibit this 
character at all. The wasp was sent on 25. i. 05, and 
specimens of S. testacea were sent in January, April, May 
and June. Examples of S. angustatum were sent in March, 
April, May and June. Two specimens of the very similar 
Pseudosphex polistes were also sent in April and May 1904. 
Fig. 8 of Rhyncopyga braconida and fig. 8a of a species of 
Braconidae are figured together to show many points of 
remarkable similarity. The two insects were not caught 
together, but at approximately the same time of year and 
at the same elevation, and it is possible and quite probable 
that they could be netted together. The moth R. braconida 
I took on March 6th, 1910, at Alto da Serra above Santos 
at 2,500 ft. The Braconid I netted on 4th April, 1910, at 
Castro at 2,900 ft. At Castro, however, on 14th April I 
took another species of Rhyncopyga, viz. meister, which is 
very similar but has the first four basal segments red below, 
while the species figured has the two basal segments banded 
red. Hither species forms almost an equally good mimic, 
but as the one illustrated is new it seems more desirable to 
figure it than the commoner and better known meisterv. 
