6. 
10. 
11. 
13. 
14, 
18, 
EMBRYOLOGICAL MONOGRAPHS. 
This layer is an enormous growth of the layer designated by the letters mu. in figure 4. cil’ Cilia at the 
actinal pole. or. Mouth. ¢a. Tentacle. At hb.3, hb.4 begin to arise sacs, which later develop into the 
circulatory-tube system. The tube / 0.3 is best marked of these. 6.1, 1.2 Remains of the original large 
cells. 
Sexually mature, ‘‘ Cydippe-formed larva,” of Chiaju (Eucharis). At the peripheral extremity of the eight 
tubes (adr. tb.) ave swollen cavities, filled with sexual products. These lie just beneath the rows of combs 
or vibratile flappers. adr. tb. Adradial tube, ultimate division of the chymiferous tubes, Which extend to 
a meridional tube below the rows of flappers. ga. Stomach. ga. tb. A chymiferous tube, in this stage 
ending blindly in the bell-walls, and called the stomach tube from its relation in position to the stomach. 
i.r.tb. Internal radial tube. There are four of these which arise from the base of the funnel and each 
divides into two adradial tubes (adr. tb.). 1.4, .° Nerves. sph. tb. Tube of the funnel, which spreads 
itself out at the upper pole (sph. tb.) under the nerve centre (nc.) Above the nerve centre is the otocyst 
with its otoliths. 
A larva at about the same stage, seen in a plane at right angles to the last. ga. Stomach, here seen in pro- 
file. adr. tb. Adradial tube. ga. tb. Stomach tube arising from the funnel (Sph.). 7.7.tb. Internal 
radial tube. .?, n.8 Nerves, a.c. Nervous centre. ta. Tentacle. ta. 1b. A tube, which passes direetly 
to the tentacle from the funnel. 7.2 A blindly ending, meridional tube under a row of vibratile flappers. 
7-+ Row of flappers. 7b. Rudimentary lobes. 
. View of a Cydippe-like larva of Chiju (Bucharis) from the actinal pole. adr. tb. Adradial tube. ex.,! ca.” 
Excretionary (?) opening. ga. Stomach. a. Nerve. #h.-tb.8 Chymiferous tubes. per. en. Canal arising 
from the base of the funnel before its division into the interradial tubes. ta. Tentacle. 
. Somewhat older larva from the actinal pole, in which the chymiferous tubes have joined in the bell-walls. 
adr. th. Adradial tube. aur.-awr.* Auricles. ex. 1. th. Tube skirting the lobe of the body, outside the 
internal tube (77. ¢b.). ga. Stomach. ga. sch. Magengefassschenkel. ga. tb. Gastric tube seen in 
section. 7i.r.db. Internal radial tube. ¢a. Tentacle. .!-z.4 Point of bifurcation of the tube which skirts 
the auricle. 
The same seen from the side. adr. tb. Adradvial tube. q@u7.1, awr.2 Auricles. ex.J. tb. External tube of 
the body lobe. ga. Stomach. ga. sch. ‘‘ Magengefissschenkel.” gaz. Sac-like appendage to the stom- 
ach. 7. 7. tb. Internal radial tube. 7b, Body lobe. mg. w. Medial gelatinous elevation near the otocyst. 
n. Nerve. ocy. Otocyst. ta. Tentacle. ta. tb. Tentacular tube. y.?, y.2 Inner wall of the body lobe, 
seen in profile. 7.°-7.® [ows of vibratile flappers. 
11-17. Development of Cestus Veneris. 
Young larva of Cestis, seen from one side. ga. Stomach. gz. tb. Tubes one on each side of the stomach. 
nJ-1.4 Nerves. or. Mouth. sph. tb. Tube of the funnel. ¢b.1-tb.4 Chymiferous tubes. 7. Vibratile 
flapper. 
. View of the ‘‘Cydippe-formed larva’ from the actinal pole. ga. Stomach. ga. th. Stomach tube. 7.7. tb. 
Internal radial tube. 7.'-n.8 Nerves. mu. Muscles. ol. Otolith. per. cn. First division of the chymif- 
erous tubes. ¢v. Tentacle. ¢b.!-1b.8 Chymiferous tubes. 
Still older larva (‘‘Cydippe form”). ga. tb. Stomach chymiferous tubes. mu. ere. Circular muscles. 
ni—n.4 Nerves. ocy. Otocyst. or. Mouth. sph. Funnel. sph. tb. Tube of the funnel. ta. Tentacle. 
tb.1-tb.4 Chymiferous tubes below the flappers. These have begun to extend downward, but in this stage 
are blind ending. 
Larva of ‘‘Cydippe form” in which the tubes (/b.) have grown downward towards the oral pole. (View at 
right angles to fig. 13.) 
adr. tb. Advadial tube. ga. Stomach. ga. tb. Gastric tube. ga. cn. Beginning of a bifureation of the 
extremity of the gastric tube. 2. c. ‘Nervous centre. sph. Funnel. ta. Tentacle. sph. tb. Tube pass- 
ing from the funnel to the otocyst. ¢b., tb.4-tb.5 Chymiferous tubes, extending meridionally in the bell- 
5 
walls. 7.5, 9.6 Vibratile flappers. . 
. Older larva than that known as the ‘‘Cydippe form "(seen in the same plane as fig. 14). ga. Stomach. ga. tb. 
Gastric tube. ga. Sac-like appendage to the stomach. m.gw. Gelatinous elevation near the otocyst. 
n. Nerve. ocy. otocyst. ¢b.8 Chymiferous tube formed by the junction of two opposite tubes (¢)., and 
th.®, fig. 14). tb.4, tb.6 Two chymiferous tubes. 
. An older stage in the development in which the chymiferous tubes (¢b.4, ¢b.5) have joined 7.8 at x.2, a3 
gw. Stomach, 7@.7./b. Internal radial tube. sph. 1b. Tube of the funnel. 
. Older embryo, in which the larva has become more elongated and band-shaped. 
18, 19, Thoé paradoxa, Chun. 
Larva (7?) of Lampetia pancerina, Chun, with single tentacle (view showing the tentacle on one side). 
ga. Stomach. ae. Nervous centre. sch. Tentacular sheath. 7.!-».4 Rows of vibratile flappers. 
tb.®, tb. chymiferous tubes under flappers ».3 and 7.4 
