The Ecology of a Sheltered Clay Bank 205 
of these utilized to good advantage the burrows or the 
nests left by the pioneers, and they in turn left many of 
their burrows for a third tenant. Among these renters 
one might also include the bees Anthophora abrupta, be- 
cause they sometimes used their old burrows for a sec- 
ond season, after enlarging and renovating them. 
Renters of Old Burrows. 
Pompilid wasp, 
Spider wasp, 
Spider wasp, 
Spider wasp, 
Monobia mud-wasp, 
Grass-carrier wasp, 
Cow-bird wasp, 
Pseudagenia mellipes. 
Try poxylon plesium, 
Try poxylon clavatum. 
Try poxylon albopilosum. 
Monobia quadridens. 
Chlorion auripes. 
Chalybion caeruleum. 
Leaf-cutter bee, Megachile campanulae. 
Osmia bee, Osmia lignaria. 
Spider, Ariadna bicolor. 
Spider, Steatoda borealis. 
(d) Visitors. 
This is a list of insects and larger animals which came 
into the community quite by accident, or in quest of food 
or shelter. In some cases they remained as permanent 
additions to the group, but in most cases, their stay was 
temporary. Many of them influenced the lives of the pio- 
neers and the renters in one of two ways: either by using 
them as food, or by giving themselves as food. 
Whether the word visitor or transients would be the 
better term to apply to this group is uncertain. Many 
insects alighted on the bank quite accidentally; others 
came there for the definite purpose of securing prey; 
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