106 CALIFORNIA ACADEMY OF SCIENCES. 



PLATE XXXVII. 



PONTODRILUS MICHAELSENI. 



5.5. A spermatheca with its diverticuhim seeu from interior of the body, wheuthe body-wall is spread out. spth. p. 

 spermathecal pore. d. diverticulum, sp?.. iuner sac-like enlargement where the spermatozoa are massed. 



56. A cross-section of the body-wall through the spermatheca near Its pore. v. I. thin vascular layer or perito- 



neum. /. m. longitudinal muscles, t. m. transverse muscles, hij. hypodermis. xpz. sjjermatozoa. int. n. 

 interstitial nuclei, en. epithelial nuclei and cells, c. m. circular muscles of the spermatheca. div. diver- 

 ticulum. 



57. A cross-section of the diverticulum of the spermatheca. in. inner nuclei of the epithelium, ints. n. inter- 



stitial nuclei, c. to. circular muscles, bl. vascular layer, gl. c. exterior glandular layer consisting of a 

 double or triple row of cells. 



58. A longitudinal section of the body-wall, somites vii, viii and ix made through the spermathecal pore, sjith. p. 



spermathecal pore. spth. the lower, enlarged part of the spermatheca, which forms a strongly muscular 

 papilla, dv. the junction with the diverticulum, set. seta. I. m. longitudinal muscles. (. m. transverse 

 muscles, a. s. anterior septum of somite viii. p. s. posterior septum of somite viii. 



59. One of the testes. 



00. A longitudinal section of one of the testes. 



61. An ovary. 



62. Longitudinal section of an ovary. 



63. Longitudinal section of the oviducal funnel, s. septum. 



