602 THE HOME OF THE BEES. 
interest to the philosophic naturalist. Special attention 
has been drawn to this “semi-pupa” state by Ratzburg, in 
his “Development of Footless Hymenopterous Larve,” 
and by Professor Agassiz, in his “Classification of Insects 
from Embryological Data” (Smithsonian Contributions), 
wherein he refers to the changes of the caterpillar of a 
butterfly (Hudamus Tityrus), just before assuming the 
chrysalis or pupa state. 
rom Mr. Emerton’s observations we should judge, 
that the pupa state lasted from three to four weeks, as 
the larvee began to transform the first of August, and 
appeared during the last week of the same month as per- 
fect bees. 
Andrena vicina is seen as late as the first week in Sep- 
tember, and again early in April, about the flowers of the 
willow. It is one of the largest of its genus and a com- 
mon species. 
Having, in a very fragmentary way, sketched the life- 
history of our Andrena, and had some glimpses of its 
subterranean life, let us now compare with it another 
genus of solitary bees (Halictus) quite closely allied in 
all respects, though a little lower in the scale. 
The Halictus parallelus Say, excavates cells almost ex- 
actly like those of Andrena; but since the bee is smaller, 
the holes are smaller, though as deep. Mr. Emerton 
found one nest in a path a foot in depth. Another nest, 
discovered September 9th, was about six inches deep. 
The cells are in form like those of Andrena, and like them 
are glazed within. The egg is rather slenderer and much 
curved ; in form it is long, cylindrical, obtuse at one end, 
and much smaller at the other. The larva (Fig. 4) is 
longer and slenderer, being quite different from the rather 
broad and flattened larva of Andrena. The body is 
