312 HYMENOPTERA ACULEATA. 



CCELIOXYS, Latr. 



An inquiline genus chiefly associating with Megachile, 

 which it much resembles in many points of structure. 

 Maxillse pointed, their palpi two-jointed, labial palpi four- 

 jointed, the basal joints sheath-like, the apical joints 

 divergent, very small and cylindrical, tongue elongate, not 

 constricted at the base, paraglossse ensheathing the base of 

 the tongue, lateral processes parallel- sided and rounded at 

 the apex, submentum very elongate and narrow, lora well 

 developed, scales at the base of the maxillae with their apices 

 fringed with hairs, labrum elongate, sharply truncate, eyes 

 hairy, antennae rather short ; wings with two submargiual 

 cells, scutellum dentate laterally ; abdomen truncate at the 

 base, each segment, except the basal one, with a deep trans- 

 verse impression, c? with the apex of the abdomen blunt, raul- 

 tispinose, sixth segment terminating the abdomen and anal 

 aperture inferior in the S , four ventral segments exposed, the 

 apex only of the fifth being visible, eighth segment tongue- 

 shaped, armature with the stipites long, straight, and hairy 

 at the apex, sagittee as long or nearly as long as the stipites, 

 coveied by the membranous spatha ; ? with the abdomen 

 subtriangular, its apex more or less acute, sixth ventral seg- 

 ment projecting beyond the sixth dorsal, c? with a stout blunt 

 spine on each of the anterior coxae. 



This is an extensive genus, occurring also in North and 

 South Africa, North and South America, and Asia, con- 

 taining many very closely allied species. The chief specific 

 characters seem to lie in the forms and sculpture of the apical 

 and ventral segments. There are only five British species, 

 which may be easily distinguished by the following table. 



(2) 1. Outer calcar of hind tibiae blunt . . vectis. 



(I ) 2. Outer calcar of hind tibiae sharp. 



(6) 3. (J with the fourth ventral segment 



emarginate at the apex ; } with the 



fifth ventral segment rounded at the 



apex. 

 (5) 4. J with the fifth dorsal segment not 



