( cLxxxiii ) 



(Bees), etc., have some of the middle joints of the front legs 

 (tibiae, metatarsi, etc.) extravagantly dilated (often "shield- 

 like"), they may be also curiously fringed, and are often 

 coloured very strangely, or so thinned as to become almost 

 membranous. T\\q front coxae in some Cerceris spp. (Fossors), 

 and likewise in various spp. of Megachile and other genera of 

 Bees, are produced spinosely at the apex. The same is the 

 case with the middle coxae of certain Odynerus spp. (Wasps). 

 In other Odynerus spp. the middle femora are excavated 

 beneath so as to appear in certain positions tridentate ; the 

 middle tibiae in some Fossors and Wasps are eccentrically 

 narrow at the base and dilated near the apex. The middle 

 metatarsus in Sphecius (a Fossor) appears, in all known species, 

 outrageously deformed. The same joint, and the middle tibia 

 also, are most eccentrically constructed in one group of Eucera 

 spp. (Bees). Bemhex spp. have often the middle femora sharply 

 denticulate along the lower margin. In Nomia and Anthophora 

 (Bees) the hind legs often show monstrous dilatations, in- 

 crassations, and distortions of particular joints. Certain 

 Stiztts spp. have a fine hair-like spine depending from the hind 

 femur. Panurgus calcaratus has a stout spur-like appendage 

 under the same joint, and its congener P. dentipes is similarly 

 armed, but on the hind trochanter. Thorn-Uke teeth or 

 tubercles occur on the front femora of one Odynerus (caroli), 

 the hind tibiae of another (probably undescribed), and one or 

 other of the leg-joints in various Bees (e. g. Eucera and 

 Anthophora spp.). Some Anthophora spp. again have the 

 middle tarsi very elongate, and either their basal or apical 

 joint, or both (but never any other), carries in front or behind 

 (or both in front and behind) a sort of fan formed of rigid 

 hairs, recalling in its outline and general appearance the tip of 

 a peacock's tail-feather. There is a somewhat similar character 

 in the apical joint of the front tarsi in Gorytes fairmairei $ 

 (a Fossor). 



In many Genera, and perhaps in some species of all Genera, 

 this strange group of characters is entirely unrepresented. 

 But whenever they occur, their forms are so constant and 

 characteristic in every case, that they are practically infallible 

 guides to a specific "determination." 



