THE CANADIAN ENTOMOLOGIST. 283 



marks chrome-yellow ; lateral marks small, nearly equilateral triangles, 

 not reaching up to antennae ; no supraclypeal or dog-ear marks ; mandi- 

 bles yellow at base, ferruginous in middle, dark at tips ; labrum dark, 

 with a central depression ; labial palpi with the first joint a trifle longer 

 than the other three united ; antennae dark brown above, chrome-yellow 

 beneath, including scape; front microscopically tessellate and with sparse 

 minute punctures ; mesothorax shining, but microscopically tessellate 

 and sparsely punctured ; tubercles yellow, but no other part of 

 prothorax ; tegulae transparent, with a yellow spot; wings milky-hyaline, 

 iridescent ; nervures white ; stigma very large, colourless, with a light 

 brown margin ; marginal cell rather obliquely truncate, the post-stigmatal 

 portion the shortest ; third discoidal cell distinct ; legs dark, anterior 

 knees, anterior tibiae except a stripe behind, and middle tibia? beneath, 

 yellow ; anterior tarsi yellowish. 



Mut. reducta. — $ . Clypeus with two very broad black median 

 bars, between which is left only a small yellow streak or triangle ; lateral 

 marks wanting or represented by two or three small spots ; tubercles 

 wholly dark ; scape without the yellow stripe ; abdominal bands narrow, 

 not reaching lateral margins, sometimes only the first two bands well 

 developed ; venter of abdomen dark. 



Hab. — San Diego, Calif., Aug. 4, 1901, at flowers of Rhus laurina, 

 Nuttall, in the immediate vicinity of the Brandegee Herbarium. The 

 plant was kindly identified by Mrs. K. Brandegee. There were taken 

 four of the type, and three of mut. reducta, all from the same shrub. 

 The dichroism of the species is quite remarkable. 



In my tables, P. rhois runs to P. bigelovice, and is especially to be 

 compared with P. Crawfordi, from which it differs by its large stigma 

 and other characters. 



While on the subject of Perdita the following may be placed on 

 record : — 



Perdita callicerata, Ckll.; Mesilla Park, N. M., June 9, 1898, one o* 

 at flowers of Atamosco longifolia (ZephyrantJies longifolia, Hemsley). 



Mr. E. S. G. Titus wishes mention to be made that his recent 

 articles on Bees in this magazine, Vol. XXXII., page 303, and Voi. 

 XXXIII. , pages 133 and 257, are to a large extent portions of a thesis 

 for the Degree of M. Sc. placed on file with the Secretary of the State 

 Agricultural College of Colorado, May 1st, 1901. 



