EXPLANATION OF PLATES. 



The following letters have the same significance in all the figures : 

 c, cuticle. 



cp, cirrus pouch. 



ev, excretory vessel. 



9vd, dorsal excretory vessel. 



svv, ventral excretory vessel. 



ga, genital aperture. 



gc, ganglion cells. 



gd, germ duct. 

 Im, longitudinal muscles. 

 ■n, nerve. 



n, ovary (germarium). 

 ov. oviduct. 



I am indebted to Mr. George T. Kline, biological artist, University of Missouri, 

 for the sketches which accompany this paper. 



3136— 22— Proc'.N.M. Vol.60 15 9 



sc, subcuticula. 



scg, subcuticular glands. 



sd, sperm duct. 



sfir, shell-gland. 



sr, seminal receptacle. 



/., testes. 



u, uterus. 



;;, vagina. 



vd, vas deferens. 



vg, vitellaria. 



yd, \T.telline duct. 



