184 P. HERBERT CARPENTER, 
connected with some ramified tubes depending into the 
celom from the oral blood-vascular ring (7, 19), but we 
have been unable to obtain conclusive evidence as to this 
oint. 
; The genital glands of the Crinoids, like those of the Star- 
fishes, are enclosed in blood spaces (figs. 9, 12, g.), the indi- 
vidual ovaries or testes at the sides of each arm being con- 
nected by a “ genital cord,” the so-called “‘ rachis” (3, 5, 19, 
28), with its enclosing blood-vessel (fig. 10,9. c’.). These 
genital cords are merely undeveloped portions of the genital 
glands, which serve to unite the isolated genital tubes, just 
as is the case in the Ophiurids (19, 27). In this group the 
genital cords of all the rays are connected by a circular one 
within the aboral blood-vascular ring; but in the Crinoids 
they, or rather the vessels enclosing them, unite into an ex- 
tensive network immediately beneath the ventral surface of 
the disc, consisting principally of larger trunks beneath the 
subtentacular canals (figs. 14, 15, g.v.), which unite laterally 
with one another and with those of adjacent rays. This net- 
work is believed by Dr. Carpenter and by Ludwig to be con- 
nected with the central plexus, though neither of them has 
succeeded in demonstrating this fact in the adult Antedon. I 
have fortunately been able to obtain one series of sections, 
which furnishes the necessary proof, while Dr. Carpenter’s 
observations of the advanced larval stages have yielded similar 
results (3,7). He found the central plexus subdividing by 
the side of the cesophageal funnel into five diverging branches, 
one of which passes into each ray beneath the commencing 
subtentacular canal, precisely in the position of the genital 
rachis of the arms. 
I have spoken above of some ramified tubes depending into 
the ccelom from the oral blood-vascular ring, with which 
both Ludwig and I believe the central plexus of Antedon 
to be connected. In Ludwig’s otherwise excellent figure of 
a section through the peristome of Antedon rosacea (19, 
Taf. xvi, fig. 39) these tubes are represented as much less 
complex in their character than they are in some parts (at 
any rate) of the peristome. Both in Ant. rosacea and in 
Ant. Eschrichtii I find a great part of the lip to be occupied 
by a large spongy mass, which consists of a dense plexus 
of closely interlaced tubes with an epithelial lining. 
Some of them are connected with the oral blood-vascular 
ring, and others, I believe, with the vessels of the central 
plexus. In Actinometra this labial plexus is much larger 
behind the mouth (¢.e. between it and the anus) than in front 
of it (fig. 14, 7.p.). It is especially developed towards the left 
