This large assemblage of Fossores is the one about which the greatest difference of opinion prevails. It is based entirely on the prothoracic characters mentioned above, and cannot be looked on as natural. We shall, however, follow Kohl[49] in treating for the present as only one family the divisions considered by many as distinct families. They are ten in number. SUB-FAM. 1. SPHEGIDES.—_Hind body with a slender pedicel of variable length; two spurs on the middle tibia. The propodeum usually horizontally elongate_.[50] This group includes a great number of species, about 200 of which are referred to the genus _Sphex_. {108}The habits of one species of this genus have been fully described by Fabre; he assigns to the species the name of _S. flavipennis_, but Kohl considers that it is more probably _S. maxillosus_. This Insect forms its nests, in the South of France, in the ground, excavating a main shaft with which are connected cells intended for the reception of the provisions for the young. The entrance to the burrow is formed by piercing a hole in the side of a very slight elevation of the soil. Thus the entrance to the construction consists of a horizontal gallery, playing the part of a vestibule, and this is used by the _Sphex_ as a place of retreat and shelter for itself; at the end of the vestibule, which may be two or three inches long, the excavation takes an abrupt turn downwards, extending in this manner another two or three inches, and terminating in an oval cell the larger diameter of which is situate in a horizontal plane. When this first cell has been completed, stored with food, and an egg laid in it, the entrance to it is blocked up, and another similar cell is formed on one side; a third and sometimes a fourth are afterwards made and provisioned, then the Insect commences anew, and a fresh tunnel is formed; ten such constructions being the number usually prepared by each wasp. The Insect works with extreme energy, and as the period of its constructive activity endures only about a month, it can give but two or three days to the construction and provisioning of each of its ten subterranean works. The provisions, according to Fabre, consist of a large species of field-cricket, of which three or four individuals are placed in each cell. Kohl states, however, that in Eastern Europe an Insect that he considers to be the same species as Fabre's _Sphex_, makes use of locusts as provisions, and he thinks that the habit may vary according to the locality or to the species of Orthoptera that may be available in the neighbourhood. However that may be, it is clear from Fabre's account that this part of the _Sphex's_ duties do not give rise to much difficulty. The cricket, having been caught, is paralysed so that it may not by its movements destroy the young larva for whose benefit it is destined. The _Sphex_ then carries it to the burrow to store it in one of the cells; before entering the cell the