62 THE ENTOMOLOGIST. 



hind margin of fifth segment darkened ; venter yellow. The abdominal 

 bands do not unite on the lateral margins. 



Hah. Tempe, Arizona, Oct. 28th, 1899 {CklL). Two females 

 at flowers of Baccharis at the foot of Tempe butte. The types 

 are nnfortimately somewhat discoloured by cj^anide. 



Allied very closely to R. toicnscndi, but differs by its smaller 

 size, nude or nearly nude mesothorax, and the entire supra- 

 clypeal mark. From P. stottleri it differs by its entirely yellow 

 femora, the entire supraclypeal mark, and the marginal cell less 

 obliquely truncate. From P. bigelovia it differs by the yellow 

 femora, shape of face-marks, &c. ; from P. zehrata by the details 

 of the face-marks, markings of the legs, &c. 



This insect finds no place in Mr. Ashmead's generic tables, 

 having the mouth-parts of Perdita, with the abdominal markings 

 of Neoperdita. 



Perdita rnellina, sp. n. 



<3^. Length about 4^ millim. ; head and thorax very dark green, 

 almost black ; nietathorax dark blue ; abdomen brownish orange, the 

 first two segments strongly suffused with black. Labial palpi with the 

 first joint longer than in typical Perdita ; clypeus with the median 

 (upper) portion small and hemispherical ; clypeus, labrum, lateral face- 

 marks, and dog-ear marks, yellowish white or very pale yellowish : no 

 supraclypeal mark ; lateral marks nearly equilateral triangles, with 

 the upper angle at the level of the antennal sockets ; mandibles white, 

 with dark tips ; cheeks simple, tbe extreme lower part white ; face 

 moderately hairy ; head large, subquadrate ; antennae yellow beneath, 

 yellowish brown above ; vertex shining, minutely and obscurely 

 granular ; mesothorax shiny, fairly pubescent ; tubercles, and two 

 transverse marks on upper border of protborax, cream-colour ; pleura 

 entirely dark ; wings slightly milky, iridescent ; nervures and stigma 

 yellowish white ; marginal cell fairly long, nearly squarely truncate ; 

 second recurrent nervure rudimentary ; femora black, with yellow 

 ends ; tibiae yellow, tbe hind tibiae suffused with blackish ; tarsi 

 yellowish white ; abdomen rather short and broad, hairy at tip, venter 

 immaculate. 



Hah. One at flowers of Heterotheca suhaxillaris, Phoenix, 

 Arizona, Oct. 15th, 1899 {CklL). P. mellina differs from P. 

 chamcesaraclm by the smooth front, differently-shaped clypeus, 

 &e. ; from P. sides by the colour of the abdomen, shorter 

 marginal cell, &c. ; from P. semicrocea by the colour of head and 

 thorax, rather longer marginal cell, &c. ; from P. rhodura by the 

 pale nervures, dark femora, colour and markings of head, &c. 



Perdita heterotheca', sp. n. 

 2 . Length about ^\ millim. ; head and thorax black, with a 

 metallic lustre; mesothorax rather brassy, metathorax bluish; head 

 ordinary, cheeks and occiput with abundant white hair, face hairy at 

 sides ; mandibles yellowish white, with ferruginous tips ; labial palpi 

 with the first joint longer than the other three combined, but not twice 



