HYMENOPTERA. — FOSSORES. 189 
species, Gorytes 4-fasciatus J’ab., at least judging from the armature 
of the legs ; but its economy has not been observed. Jig. 80. 6. ex- 
hibit the legs of Miscophus bicolor, observed by me to burrow in sand ; 
the fore legs are, however, very sparingly armed with short simple 
spines, and the hind tibiz nearly simple; and jig. 80. 7. are details of 
Cerceris arenaria, a true sand burrower ; having the fore legs very 
strongly ciliated, and the hind tibiz armed with many short strong 
spines. Other figures, illustrating the fossorial structure of the legs, 
will be found under the family Sphegidz ; in which also will be found 
the details of Ceropales maculata, a species having perfectly simple 
legs, and regarded as a parasite. 
Although there is much general similarity in the habits of the truly 
fossorial species, there is considerrble diversity in the details of their 
proceedings: thus, whilst Oxybelus conveys its prey by means of its 
hind legs, Pompilus and Ammophila walk backwards, dragging it 
with their mandibles. “ Astata, Tachytes, Psen, Crabro, Mellinus, and 
Cerceris, fly bodily and directly forward with it in their mandibles, 
assisted by their fore-legs.” (Shuckard, |. c.) From my own observ- 
ations, each species appears ordinarily to confine itself to its own 
particular prey. Instances are on record, however, in which con- 
siderable diversity in the prey of the same species has been observed : 
this probably arose from the female not being able to discover her 
legitimate prey; thus Serville and Saint Fargeau state that Bembex 
rostrata indifferently collects the species of Eristalis, Stratiomys, and 
the larger Muscide ; but it may be regarded as the ordinary rule,that 
each species confines itself to its peculiar prey: thus, numbers of the 
same species of fly or larva are found in the same cell, although this 
must sometimes be a matter of difficulty; as, in the case recorded by 
Réaumur (tom. vi. p. 272.), where numbers of individuals of a species 
of Anthrax, “ plus rares qu’aucune des [mouches] précédentes,” were 
found “ dans d’autres trous ;” and in other cases mentioned to me by 
the Senator Van Heyden, of Frankfort, and M. Audouin, in which 
numbers of the very rare Ogcodes gibbosus had been thus stored up 
by one of these insects for its young.* The prey is, moreover, very 
various, comprising insects of nearly every order; the Coleopterat, 
* Réaumur also figures (tom, vi. pl. 27.) cells separately filled with numbers of 
specimens of a Chironomus? Tetanocera? and Thereva? = «= 
+ Mr. Shuckard states that he knows only one instance in which a Coleopterous 
insect is subject to the attacks of these Fossores; namely, Strophosomus, one of the 
Curculionidae, preyed upon by Cerceris arenaria. Lixus Ascanii, and several other 
Curculionidz, are preyed upon by seyeral other species of Cerceris. (See infra.) 
