The Ecology of a Sheltered Clay Bank 227 
the cuckoo-bees, the silver-winged parasitic Dipteron 
made its appearance. ' 
On August 30, only one cuckoo-bee was present; this 
seemed a forerunner of the second generation, rather 
than a straggler from the first, for the next day three 
were out, and thereafter they increased briskly until a 
thriving second generation was out and in action. From 
September 4 to 6 this population was at its height; by 
September 12 they, along with the other species then 
about the bank, began to disappear as the chill nights 
came on, but whether they perished with the cold, or 
made their natural demise, or merely were in hiding, I 
cannot say with certainty. However, on one late Sep- 
tember day, when the bank became warm in the sun- 
shine, two appeared; one was especially active in annoy- 
ing a turret-bee. No doubt many of these parasitic bees 
died in their burrows. Their latest date recorded was 
October 13. 
Few of these superchitinous insects fall prey to the 
hungry neighbors. The rule ‘‘to eat and be eaten’’ 
does not apply to the cuckoo-bee, which appears to be 
the armadillo of the insect world. 
Pseudomelecta interrupta Cress, [S. A. Rohwer]. This 
bee was seen only once at the clay bank, on July 
21, 1920. It entered one of the nests of Anthophora, 
and was taken for identification as it emerged several 
minutes later. hice 
The species must have a highly interesting life his- 
tory, for Wheeler (Proc. Am. Phil. Soc. 58:14. 1919) 
classifies it as one of the parasitic bees, derived from 
the ancestral genus Anthophora and probably parasitic 
on Anthophora. He questions this later statement, but 
since it entered the burrow of Anthophora after the 
