378 Trans. Acad. Sci. of St. Louis 
tions out of pith and saliva, and, unlike the Eumenids, 
cannot carry water or mud to do the work of a mason, 
but, being deficient in all the talents that make for good 
workmanship, she picks up what she can and makes the 
best of it. Furthermore, she probably succeeds, in so 
far as the prosperity of the species is concerned, for the 
young in the cocoons seemed to be healthy and unusually 
free from parasites. 
‘A second nest was found near by, which was just the 
Same in measurements and structure; the only differ- 
ence was that in the pack of debris 114 inches long there 
were three cococns instead of five. It was clear that 
this twig also had been previously inhabited, for the 
bottom 4 inches was filled with coarse pith mixed with 
particles of broken cocoons and the inedible parts of 
flies. Just while I was examining the stem on the morn- 
ing of July 4, one broke its cocoon and crept out. This 
first-born was a male. 
Twie Wasp, Solenius interruptus Lep. [S. A. Rohwer]. 
In the cut stem of a low catalpa in the Tower Grove 
Park a nest of Solenius interruptus was found on Febru- 
ary 13, 1920. The cocoons appeared like those of a Hy- 
pocrabro, but the plan of the nest was just like that of 
Diphlebus biparitor, described elsewhere in these pages. 
A tunnel was dug down one side of the pith chamber; 
two cells were made in the bottom of this by inserting 
partitions of pith across it, and above that point lateral 
tunnels or pockets branched off which served as cells. 
The main gallery here was filled with pith chips. On May 
18, one adult of S. interruptus emerged, proving the own- 
ership of this nest. 
