406 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 54. 



The larva of Stylops swenki is illustrated in text figure 1 and of 

 Stylops calif ornica on plate 71. 



It is presumed that the first elongate joint of the leg is the femur, 

 although it may be the trochanter. In the latter case tarsus would be 



Fig. 4.— Myodites solidaginis Pierce, a, triungulinid, ventral 

 view; 6, POSTERIOR leg; c, posterior coxa; d, pulvillus, lateral 

 view; e, pulvillus, ventral view; /, mouth parts, ventral view. 



absent in Stichotrema (pi. 67), Stylops (pi. 71, fig. 7), etc., and the 

 writer is not willing to accept this view. 



Aberrations. — Hoffman (1914&) describes aberrant triungulinids 

 of Xenos hohlsi Hoffman and Eupathocera spTiecidarum Dufour. 



The female structure is not subject to as many modifications as that 

 of the male. In fact, so few are the characters that the writer had 



been obliged to use comparative measure- 

 ments of the dimensions of the cephalo- 

 thorax to separate species. Figure 5 

 represents a generalized female cephalo- 

 thorax and shows the location of the 

 measurements which are used throughout 

 the present paper. Measurement No. 1 

 is the width at the spiracles (posterior 

 pair when two occur) ; No. 2 is the width 

 of the base of the head; No. 3 is the 

 width of the head at the emargination 

 . near the base of the mandibles; No. 4 is 

 the width of the cephalothorax at the base ; No. 5 is the length from 

 the front edge of the spiracle to apex of head; No. 6 is the length 

 from base to apex of cephalothorax. 



Fig. 5.— Diagram illustrating meas- 

 urements used in describing fe 



MALE cephalothorax. 



