432 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL, 54. 



160 mm. tube length, 1 inch eyepiece micrometer, 16 mm. objective. 

 The measurements represent spaces on the micrometer scale in which 

 one space =0.0149 mm. 



The measurements are given by number as follows : 



1. Breadth of cephalothorax at spiracles. 



2. Breadth of head at base. 



3. Breadth of head at base of mandibles. 



4. Breadth of basal constriction of cephalothorax. 



5. Length from anterior edge of spiracles to apex. 



6. Length from base to apex. 



These measurements are also given in a second table under each 

 species comparing them proportionately with measurement No. 1. 

 (See text fig. 5, p. 406.) 



Table of measurements. 



This shows what a different mathematical formula this species has 

 from the genus Stylops. 



Triungulinid (pi. 68, figs. 4-7) : Elongate, hexapodal. Head trans- 

 verse, emarginate, with five ocelli in a dark patch on each side. These 

 ocelli are completel}'^ separated, perfect, simple eyes with rather large 

 lenses and the outline of the entire eye darkened. The crystal body is 

 funnel shaped, extending through the ocellus. Mandibles elongate, 

 slender, curved, turned backward, and apparently with an opening in 

 the enlarged tip. The pharyngeal skeleton is much more slender 

 than in Stichotretna, consisting of an arched piece and two almost 

 straight diverging rods. The antennae are very indistinct even with 

 the highest power magnification, but seem to be composed of two 

 joints and a filament. 



The coxae are very large ; femora and tibiae apically spined ; tarsuf 

 one jointed, terminated apparently by three slender filaments. This 

 is a very unusual type of tarsus for Strepsiptera. The eighth, ninth, 

 and tenth segments of the abdomen are greatly modified. The eighth 

 laterally extends almost to the apex of the ninth, but is dorsally 

 emarginate and ventrally is normal. The ninth incloses the tenth, 

 which bears a pair of stylets. 



Types (female and triungulinids) . — Cat. No. 21436, U.S.N.M. 



8. CHRYSOCORIXENOS, new genus. 



Female with five unpaired genital tubes, and two pair of cephalo ■ 

 thoracic spiracles. Cephalothorax very elongate, only narrowing in 

 front of base of head. 



