282 Ur. T. D. A. CockexQW— Descriptions and 



May 12, by sweeping herbage {Cockerell). It runs in my 

 table of Perdita (Proc. Acad. Nat. Sci. Philad. 1896) to 

 P. maculipes, from which it is easily known by the dark 

 brown stigma, the pleura with only an oblique yellow band, 

 and the abdominal bands not united at sides. The dark 

 mark on anterior tibia is small, and if the dark markings 

 on anterior and middle legs were absent it would run to the 

 vicinity of salicis, nitidella, and exclamans, where it would 

 readily be known by the dark stigma. The face is pale 

 yellow, and the upward extension of lateral marks is like a 

 closed hand with a very short index-finger pointed ; there is 

 a yellow band along lower half of posterior orbits. The 

 second s.m. is not so greatly narrowed above as in the type 

 female. The ventral surface of the abdomen is yellow 

 without markings. 



Perdita blrkmanni, sp. n. 



? . — Length 4 mm. or slightly over. 



Head and thorax dark bluish green, dullish, only slightly 

 hairy ; head ordinary; clypeus (except the usual dots and 

 a pair of brownish bars), a very small transverse supra- 

 clypeal mark (sometimes having the form of a letter C), 

 lateral marks (broad below, narrowed above, ending obtusely 

 on orbital margin at level of antennpe), labrum, and mandibles 

 (except the rufescent apices), all yellow ; cheeks without 

 yellow ; antennae rather long, flagellum pale fulvous be- 

 neath ; tubercles with a pale yellow mark ; tegulae testaceous. 

 Wings strongly dusky, outer r. n. and t.-c. pallid and weak. 

 Legs dark brown, with the knees, and anterior and middle 

 tibiae in front yellow. Abdomen with a yellow mark at 

 each side of first four segments, those on first small, the 

 others pointed mesad, not or hardly oblique ; venter brown. 

 The stigma is sepia, Avithout a hyaline centre. 



Hab. Fedor, Texas, June 1 {Birkmarm, 89). Two 

 specimens. 



In my tables of Perdita this runs to P. afinis, var., but it 

 is known by its small size and other characters. It is much 

 smaller than P. octomaculata, Say, and has the lateral face- 

 marks differently shaped, without the strong inner angular 

 notch. Among the Texas species it falls close to P. jonesi, 

 Ckll., but differs by being smaller, with the yellow marks 

 on third and fourth abdominal segments transverse (not 

 oblique), supraclypeal mark present, anterior tibiae entirely 

 yellow in front. 



