147 
ample proportions, a good inch long, oval and horizontally formed 
and with smooth solid walls. Many held beetles and wasp larvae 
or eggs, while others contained cocoons. The provender was 
more or less flexible and well preserved, but in all cases stung to 
complete immobility. All told, I dug out 14 species of beetles 
from these cells, two large species of Anthribidae and the re- 
mainder long-horn beetles of the subfamily Lamuinae; the largest 
of these measured 21 mm. long or about ‘the length of the wasp 
herself. Another beetle measured 19 mm. The two Anthri- 
bidae, with their long antennae, much recall a long-horn beetle 
and one might suggest that the similarity deceived Cerceris into 
catching beetles outside her accustomed group. Perhaps my ob- 
servations on the next species will dispel this idea. ; 
The egg of Cerceris angularis is proportionately large, for it 
measures 6 x 1.08 mm. and is thus the equal of those of some of 

Io Te Fig. 78. mien 79: 
Beetle showing egg Full- grown larva Cocoon of C. angu- 
of C. angularis, X of C. angularis. laris. Natural 
4/3. Natural size. size. 
the large Chlorion. It is shining white, slightly curved and a little 
broadest at the head end. It is fixed along the underside of the 
beetle (Fig. 77) in such wise that the head end rests upon one of 
the fore coxae. 
Cerceris grubs seem difficult to rear ; their natural life in the 
damp cells is a condition hard to imitate. Thus I did not get 
much data on their growth. Younger individuals are whitish, 
and those about to spin cocoons lemon yellow. A full-fed indi- 
vidual is 28 mm. or over an inch long, well segmented and pro- 
portionately slender. There is no need here even of a moderate- 
sized head : the small and comparatively long head with sharp and 
slender mandibles and elongate underlip fit it well for forcing 
apart the segments of the corselet, etc., of its heavily-armored 
food supply, and the grub’s slender thorax, capable of much 
extension, follows the head into the beetle’s body to get at the 
meat. The abdomen terminates in an unevenly-lobed and narrow 
cylinder (see Fig. 78), apparently a character of Cerceris larvae 
