178 THE ENTOMOLOGIST. 



other female. The species is quite distinct from P. monardce, 

 Viereck. 



Perdita dallasiana, n. sp. 



S' . Length just over 4 mm. ; head and thorax rather yellowish 

 green, marked with yellow ; thorax, upper part of head, and cheeks 

 conspicuously though not densely hairy ; head round, cheeks normal ; 

 face entirely pale dull semipellucid yellow up to level of autennge (this 

 also including labrum, and mandibles except the extreme tip, which is 

 reddish), the light colour having a broad but short angular projection 

 upwards in the middle line, and on each side meeting the orbital mar- 

 gins at an angle of perhaps 60"^, the apical point, however, sending a 

 line upwards, which diverges a little from the eye ; cheeks, except the 

 upper part, yellow ; antennae light yellow beneath and dark above ; 

 front dullish ; prothorax light yellow with a green transverse band, 

 which reaches the hind margin for a short distance in the middle line ; 

 mesothorax rather shiny, the median groove very distinct ; pleura with 

 two yellow marks, one just behind the tubercles, and a larger trans- 

 verse one lower down ; legs very light yellow, marked with very dark 

 brown ; all the femora have large marks behind, as also do the tibife ; 

 tegulffi pellucid ; wings very iridescent, with brown nervures, the 

 stigma narrowly margined with brown ; marginal cell ordinary ; third 

 discoidal cell weak ; first five abdominal segments with broad dull 

 yellow entire bands on a dark brown ground ; those on segments two 

 and three bend abruptly backwards at the sides, leaving a brown tri- 

 angular antero-lateral corner on each side of the segment, and prevent- 

 ing the brown from reaching the lateral margins posteriorly ; on seg- 

 ments four and five the lateral backward processes are wanting, and so 

 the bands end some distance from the lateral margins ; segments six 

 and seven entirely yellow ; ventral surface of abdomen entirely yellow, 

 rather inclining to orange. Runs in my tables to P. hirsnta, Ckll., 

 though the hair of the front, while arranged as in hirsnta, is not so 

 conspicuously abundant. It may be known from hirsnta by the yellow 

 line extending upwards at the sides of the face, the greater amount 

 of yellow on cheeks, the marks on pleura, the colour of the hind 

 legs, &c. 



Hab. Dallas, Texas, on Helianthus, July 13th, 1905 (W. W. 

 Yothers) ; also a specimen with the marking of the abdomen a 

 little different, from Eosser, Texas, June 7th, 1905 (C. K. Jones). 



Perdita xanthismce sideranthi, n. subsp. 



? . Runs in my table (Proc. Phila. Acad. 1896) to P. austini, but 

 is not related to that species. The form with a supraclypeal mark runs 

 near P. stoUeri, but difl'ers by the higher clypeus, much duller meso- 

 thorax, &c. It differs from true xanthismcB as follows : dog-ear marks 

 absent ; supraclypeal mark absent, or rarely represented by a narrow 

 transverse band ; abdomen dark brown or practically black, with broad 

 cream-coloured bauds on segments two to five, these bands notched in 

 the middle posteriorly ; venter darker. 



This certainly looks like a distinct species, but the abdomen 

 is very variable, and the lightest specimens do not differ materi- 



