96 THE ECHINODERMATA. $ OT. 
§ 97. 
In the Crinoidea, these organs, in the form of tubes, are situated under 
the soft perisoma of the pinnulae, and probably are without proper excre- 
tory ducts.” ; 
In the Ophiuridae, they consist of lobular, pedunculated sacs, which are 
suspended in pairs in the inter-radial spaces of the disc. 
These ten organs are usually deeply fissured, and the lobules thus formed 
appear as so many proper sacs attached to the peduncle.” These last are 
sometimes subdivided also. ; 
Sometimes each organ, divided in its whole length into lobules, is turned 
in the shape of a ram’s horn. The peduncle of these organs is directed 
towards the mouth, but it is yet uncertain whether their contents escape 
this way or fall into the cavity of the body. In the first case, the pedun- 
cle would be the excretory duct ;® and in the second, the eggs and sperm 
would escape through the respiratory openings. 
In the Asteroidae these organs consist of varicose lobular sacs, situated 
in the angles of the inter-radial spaces.” In those species which are without 
an anus, there are no proper genital openings; ® these openings are also 
wanting in those Asteroidae which have an anus. In these last, the sperm 
and very small eggs pass into the cavity of the body, and probably have 
their escape through the respiratory openings. 
But in some species,“ there are upon the back and near each angle of 
the inter-radial spaces two small approximated plates, perforated by small 
openings (Laminae cribrosae). 
These are the simple openings of these 
organs, which here consist of multi-ramose sacs, situated all along each side 
of the inter-radial septa, to the common duct which opens through one of the 
plates. 
The number of these genital sacs varies widely in the different genera 
of the Asteroidae. 
In many, a single trunk of them hangs on each side of 
the inter-radial septa ;* in others, there is a whole row of them ;® and in 
others still, there are two rows attached to the dorsal surface of the cavity 
of the body, and extending into the rays." 
In the Kchinoidea, these organs descend along the internal surface of 
1 The development of the genital organs of 
Comatula was first observed by Dujardin, who 
asserts that the red vesicles situated on both sides 
of the tentacular furrows secrete, during the epoch 
of rut, a very beautifully red liquid (L’Instit. No. 
119, p. 268, or Wiegmann’s Arch. 1836, II. p. 
207). Thompson has seen the eggs of Comatula 
escape in clusters through the openings of the pin- 
nulae (Edinb. New Philos. Jour. No. XX. p. 295, 
or Froriep’s neue Not. No. 1057, 1836, p. 4, fig. 
8); while, according to Muller, they escape by 
rupture (Abhandl. d. Berl. Akad. 1841, p. 234, Taf. 
V. fig. 17, 18). 
2 Ophioderma longicauda, and Ophiolepis 
scolopendrica ; see Rathké, Foriep’s neue Not. 
No. 269, p. 65; and, Neueste Schrift. d. Natur- 
forsch. Gesellsch. in Danzig. IIL. Hit, IV. 1842, p. 
116, Taf. II. fig. 3, 4. . 
83 Ophiocoma nigra; see Rathké, Danzig. 
Schrift. &c. loc. cit. Taf. IL. fig. 5-7. 
4 Ophiothriz fragilis. 
5 Rathkeé, loc. cit. . 
6 Miller and Troschel, loc. cit. p. 123. 
7 Miller and Troschel have very interesting 
details upon the various arrangements of the geni- 
tal organs of the Asteroidae (loc. cit. p. 132). 
8 Asin Astropecten and Luidia. 
9 As in Ophidiaster. 
10 According to Sars, the ventral surface of the 
disc and arms of the female Echinaster sanguin- 
olentus and Asteracanthion Miilleri have at cer- 
tain times a kind of incubating cavity, in which the 
eggs remain during their development. He thinks 
they get there from the cavity of the body, through 
particular openings upon the ventral surface of this 
last ; see Wiegmann’s Arch. 1844, I. p. 169, Taf. 
VI. fig. 1, 2. 
The genital parts of Echinaster sanguinolentus 
have been described with much detail by Sars, 
Faun. littor. Norveg. p. 48. 
ll Asteracanthion rubens, and Solaster pap- 
posus ; see Muller and T'roschel, loc. cit. Taf. 
XII. fig. 2-4. 
lz Echinaster, Astrogonium, Asteriscus, and 
Ctenodiscus. 
18 Astropecten, Oreaster, and Culcita; see 
Tiedemann, loc. cit. p. 61, Taf. VIII. L. L. 
14 Archaster, Chauetaster, Luidia and Ophidi- 
aster ; see Muller and Troschel, loc. cit. Taf. 
XI. fig. 5. 
