Insects 205 



black, not metallic as in most Osmia. There is no pulvillus be- 

 tween the claws, such as exists in Osmia and related genera. 



(6) Coelioxys is a curious genus, parasitic in the nests of 

 Megachile, rather easily known by the hairy eyes. The females 

 have the end of the abdomen lengthened and sharply pointed; 

 in the males it is short and spiny. We have 22 species, but their 

 association with particular host-bees has never been ascertained, 

 with the exception of a couple which were studied by Graenicher 

 in Wisconsin. 



(7) Melissodes and Tetralonia belong to the Eucerine Anthop- 

 horidae, and are peculiar for having the antennae extremely long 

 in the males, but short in the females. The males also nearly 

 always have the face yellow or whitish, while in the females it 

 is black. Thus the sexes are surprisingly different, and have 

 sometimes been described as different species. In all, the tongue 

 is very long, and there are three cubital cells in the front wings. 

 Tetralonia, with black antennae and six-jointed maxillary palpi, 

 appears in the spring or early summer. Later in the summer we 

 find numerous kinds of Melissodes, mostly with the antennae 

 reddish or bright ferruginous beneath, and all with the maxillary 

 palpi four jointed. The primitive number of joints in the max- 

 illary palpi of bees is six, and in the course of evolution we find 

 these numbers variously reduced. Thus Melissodes is more 

 modified than Tetralonia. A closely related genus, Xenoglossa, 

 has species which may be found in the flowers of squash and 

 similar plants. Its maxillary palpi have five joints. 



(8) Anthophora, the type of Anthophoridae, has sixteen 

 Colorado species. Several of them are large and robust, almost 

 like humble-bees, but easily known from them by the wings, and 

 the light surface of the face in the males. The tongue is very 

 long, and there are six joints to the maxillary palpi. The male 

 antennae are not unusually long. These bees nest in holes in 

 banks, and make a little extension or porch over the opening. 

 The work is all done by the females, but the males may sometimes 

 be seen with their light faces at the openings of the burrows, 

 serving as doors to keep out intruders. In spite of all precautions, 

 a very curious beetle (Leonidia neomexicana) is able to live as a 

 parasite in the nests. It cannot fly, but its larvae are doubtless 

 transported clinging to the bodies of female bees. 



