60 CALIFORNIA ACADEMY OF SCIENCES. 
63. Inner part of nephridium more highly magnified. The numerals indicate the same places as in Fig. 59. The 
letters are the same as in the above figure. 
64. Part of the same more highly magnified in order to show the capillaries and their connection with the inner 
duct of the tube. ¢./. tube leading to nephridio-stome. a. upper canal. b. lowercanal. j. /. inner lumen 
of the duct which connects at c. with the capillaries. c. ¢. capillary tubes, longitudinal view. c.¢.¢. capil- 
lary tubes seen in cross-section. sp.c. spongy canal or tube directly connecting with the duct 1 and con- 
taining the capillaries. 0. c. outer canal leading to the nephridio-pore. c¢. br. the narrow bridge connecting 
the two main folds. p.c. point where ciliation begins. bl. v. blood-vessels, connectmg with capillary 
blood-vessels surrounding the two inner canals @ and; only a part of the blood-vessels are drawn. This 
figure was carefully drawn with camera lucida, though, on account of the minuteness and numbers of the 
ductules c. fe. and c. ¢., it was impossible to delineate all, almost one-fifth having been left out in places where 
they crowded each other. 
65. View of the spongy duct between 3 and 4 showing the inner canals a and } and the connecting ductules; 
letters indicate the same as in previous figures. 
66. The same spongy duct near 4, end view, and partly cross section. 
67. The posterior fold as seen at 5, the crosses + and X indicate the respective point corresponding on fig. 59, 
in order to show the direction of the tube, which is contrary to the one shown on fig. 59. sp. ¢. the spongy 
tube with the upper and lower ducts, connected by ductules c. ¢. bl. bloodvessels. cap. capillary blood- 
vessels, some of which surround the inner canals, others the outer fold. At the place marked with a x the 
ductules begin to connect the upper spongy tube with the lower main canal instead of with the lower part 
of the spongy tube, as at c. ¢. 
68. A somewhat larger figure of the last taken at the end x, where the lower part of the spongy tube has almost 
vanished and become bereft of its tubules c.¢., capillary tubes entering canal b. c. chambers on the central 
canal in the spongy tube, which send off tubules on the other side of the two main canals, and which also 
enter the canal. 6.1. lumen of the spongy tube. In this and the previous figure will be seen how the tubules 
of the spongy tube shown in figs. 65 and 66 have been found forming a more regular lumen /, which in the 
next figure will be seen to emerge into or change to a regular canal. 
69. Part of the upper fold at 7, showing the tubules of the spongy tube to cease, the tube itself to become more 
regular, fusing itself in canalb. The arrows show the direction of the fluid or excretions from the nepridio- 
stome to the pore. 
70. Diagramatic section of the main fold at the place where the capillaries of the spongy mass have ceased, and at 
the very point of the outer band marked fig. 59 0. c.f. The spongy mass surrounding the canals is now void 
of tubules. 
71. View of the anterior fold at 10, showing the inner ciliated canal—formerly the lumen of the spongy tube— 
and the two canals a and 4, which are enclosed by a common glandular mass, a continuation of the spongy 
tube. The lower fan-shaped lines are possibly openings or valves in the tube, connecting with the glandular 
mass. As will be seen, the glandular mass is not continuous, but seemingly separated by lumens—/—which 
may prove to be canals connecting with the tube at the slits above referred to. 
72. A part of same fold between 9 and 10. The lumen is here void of cilia, and the glandulous mass is smaller 
73. ‘The main fold as seen at the narrow place 9, 7. lumen void of cilia. «. one of the canals a or b seen on the 
other side of the limen. 6/. y. bloodyessels surrounding the lumen and its glandular walls. 
744. Cross section of the posterior main fold taken at 8, before the main central lumen in the spongy duct was 
formed. 
74B. Cross section of the posterior duct at 7, showing the blind ending of the tubules. 
75. A longitudinal section of the fold at 5, showing only one of the central canals. 
76. The same, the under side of the lumen being in focus. 
77. A longitudinal section near 3; here also one of the canals has been cut away. 
78. Peritoneal cells of the nephridial supporting covering from p. c. fig. 59. 
79. The same, end view. p.c. masses of perigastric cells. 
80. One of the perigastric cells more highly magnified. 
81. One of the spermathecs, exterior view. 
$2. Cross section of a spermatheca. a. upper sac-like part. b. lower muscular part. m. muscular layer of the 
sac-like part. /. m. longitudinal muscular layer of the body-wall. c. m. circular muscular layer of the 
spermatheca. gl. ep. glandular epithelium. 7. inner cavity of the spermatheca. sp. b. sperm balls. /. s. 
lacunary system, or chambers for the storage of the spermatozoa. s. m. secreted mass with streaks of sperm- 
atozoa. spz. spermatozoa. ¢.m. transverse muscular layer of the body-wall. spth. p. spermathecal-pore. 
83. A longitudinal section of the spermatheca more highly magnified, showing the lacunary system and its position 
to the epithelial cells. Letters as in the last figure. 
54. Cross section of the muscular part of the spermatheca, showing the arrangement of the storage chambers oc- 
cupied by sperm balls. Letters as in fig. 83. 
