458 Illinois State Lahoratori/ of Natural History. 

 EXPLANATION OF PLATES. 



ABBREVIATIONS. 

 (it., atrium. ". c, nerve cord. 



(■lit., clitellum. pr. spermiducal glaud. 



ca'L, c(plom. p. r. I. v., posterior ventral lateral 



vessel. 

 (I. 1. v., dorsal lateral vessel. •''■fP-, septum. 



(/. v., dorsal vessel. .sp. eh., spermiducal chamber. 



g. p., genital papilla. sp. d., sperm-duct. 



g. N., genital seta. sj). fh.., spermatheca. 



g. s. gl , gland of genital seta. -s-p. .s-., sperm-sac. 



/. r., lateral vessel. c »., integumental vascular 



network. 

 m., muscles. ''. >\, ventral vessel, 



m. ('. /. v., median ventral lateral vessel. po., spermiducal pore. 



Plate XXXIX. 



Emholocephalus multisctosiis. 

 Fui. 1. Anterior part. X 18. 

 Fig. 2. Set*. X 250. 



a and b, from ventral bundles. 



c, palmate seta from dorsal bundle. 



d, distal end of same. 



Fig. 3. Sections of sperm-duct, x 180. 



Rhizodrilus l((ctetts. 

 Fig. -I. Setae, x 250. 



a, ordinary uncinate seta. 



b, genital seta from IX. 



c, genital setfe from XI. 



Pig. 5. Transverse section through spermiducal chamber. X TO. 



Plate XL. 



IlhizodrilHS lactcKS. 



Fig. 6. Sagittal section through genital papilla, seta, and gland of IX., 



combined from several sections. X 180. 

 Fig. 7. Transverse section through spermatheca^. X TO. 

 Fig. 8. Diagram of blood-vessels in VII-IX. 



Ilyodrilns coceiiieiis. 



FiG.lt. Diagram of bloodvessels in \' VIII., adapted from a figure by 

 Stole. 



Verinicidiis pilosus. 



Fig. 10. Diagram of blood-vessels in IV-VI, from a figure by Goodrich. 

 Those of VII-X are similar. 



