186 CALIFORNIA ACADEMY OF SCIENCES. 



PLATE LI. 



ALEODRILUS KEYESI. 



71. Crosa-seetioii throu<<h somite ix, showing the septal ylauds and the thickeued septa, x. ijl. septal gland, the 

 prolougatiou of \ihich probably connects with the intestine and the median blood vessel, x. at this point the 

 ventral vessel and the septal gland have been bent and cut twice. 



73. Cross-section through somite .\ii, showing the posterior sperm-sac. Ir<i. trabecula. v. v. ventral vessel in two 



successive somites, s-pc. sperm-cell germinative area of colls with narrow nuclei. 



74. Section through apical part of spermathcca. 



75. Section through intestine and septal gland in somite x, anterior to fig. 72, showing discharge duct of septal 



gland. The ventral vessel and heart have been folded and cut three different times; similarly part of the septal 

 gland has been cut twice, d. discharge duct of septal gland; it probably reaches in between the epithelial 

 cells of the intestine. 



77. Section through dorsal median vessel, where it connects with two lateral vessels; the section goes only through 



one of the points of connection. The lateral vessels are covered with chloragogeu cell. 



78. Section through the suspended posterior part of the spermduct in the anterior part of somite xii. The duct is 



seen suspended between two mesenteric strands, one connecting with the heart, the other with the septum 

 close to the body wall. h. v. heart valve, yl. gland emptying in spermduct. 



79. Section through spermduct in somite xi, the cut going through testis, which is immediately superposed on the 



duct or rather the posterior part of the ciliated rosette. 



80. Section through spermduct going through the ovary iu xiii. a. sjul. spermduct from anterior rosette, already 



attached to the body wall. p. sjnl. spermduct from posterior rosette, yet suspended and passing through the 

 ovary, ov. ovary with full-grown ova, with germ-cells and with a germinative area where cells are in mitosis. 

 The nuclei in the germ-cells are oval, while those in the grown ova are round. Zeiss D. Eyp. 2. 



81. Section through si)crniduct through one of the posterior somites where the two ducts have joined iu the body- 



wall, clil. clitellum in xiv. 



