REVISION OP STREPSIPTERA PIERCE. 127 



Female. — The following description is drawn from the typical 

 material : 



Length of cephalothorax 1.47 mm., breadth at spiracles 1.30 mm., 

 breadth at base of head 0.94 mm., distance between mandibles at 

 base 0.28 mm. Cephalothorax dark brown except in front of line 

 between posterior lateral corners of head, which portion is much 

 lighter; considerably longer than broad, very slightly constricted at 

 base, convex from base to spiracles, thence oblique and almost 

 straight to base of head, thence unevenly sinuate; apex truncate, 

 sinuate; spiracles not laterally prominent; mandibles distant from 

 lateral margins of head, oblique, oblong, with outward curved tooth 

 on inner margin. 



ACROSCHISMUS PALLIDUS TEXENSIS, new variety. 



Material collected at Rosser, Texas, in August, 1905, by F. C. 

 Bishopp and C. R. Jones from Polistes annularis has been called 

 Acrosclrismus pallidus by the writer, but a careful comparison of the 

 descriptions of A. pallidus and A. nigrescens indicates a varietal 

 tendency; hence the convenience name texensis (fig. 3, nos. 9, 10; pi. 

 7, figs. 1, 5, 9; pi. 8, figs. 2, 3; pi. 9, figs. 5, 6). 



Male. — Size: texensis, specimens measure respectively 2.6, 2.8, 2.8, 

 3, 3, 3 r 3, 3, 3, 3.1, 3.2, 3*.2, 3.3, 3.4, 3.5 mm.; i. e., 2.6-3.5 mm.; 

 pallidus, 2.25-2.75 mm. (Brues) ; nigrescens, 4.5 mm. (Brues). Anten- 

 nas: texensis, first joints pale, third and fourth darker; pallidus, first 

 joints pale, third and fourth darker (Brues) ; nigrescens, dark cinereous 

 (Brues). Mandibles: texensis, entirely pale yellow; pallidus, pale 

 luteous to white (Brues) ; nigrescens, black to lighter (Brues) . Maxilla 1 : 

 texensis, distinctly jointed, pale; pallidus, distinctly jointed, pale 

 (Brues); nigrescens, indistinctly jointed, cinereous (Brues). Wing 

 nervures pale, weak; texensis, radius ("subcosta" Brues) inter- 

 rupted at node; pallidus, radius not interrupted (Brues); nigrescens, 

 radius interrupted at node (Brues) . 



The following accurate measurements were taken by microscope 

 and may best be considered from the comparative standpoint. A 

 Bausch and Lomb instrument, with two-thirds objective and 2-inch 

 eyepiece, tube length 160, is the standard. The figures given below 

 are in spaces which measure 0.0157 mm. The same scale is used 

 later for other species. 



Antennas: Length = 55; fourth segment = 48; greatest breadth = 

 6.5. 



Head: Distance between outer basal corners of antennas = 17; 

 between inner front edges of eyes = 27 ; between inner hind edges of 

 eyes = 42 ; breadth of head = 54. 



Mouth parts: Mandible = 22; maxilla =10; distance to base of 

 palpus or second joint = 6; palpus = 6. 



