380 
normally they occur only along each side of the mesentery and in 
a series in the left dorso-lateral interradius; but then, further, they 
may occur along both sides of the left ventral interradius, along 
the radial muscles, and finally in some specimens there are 10 
longitudinal series of ciliated funnels, one along each side of all 
the radial muscles. Their shape and size is given in fig. 60.b. 
0 
tig. 61. Series of developmenfal stages of hooks of 
Trochodota diinedinensis. 220 /, 
n // i “C gunaus are rattier 
short, generally bending 
forwards so as to lie 
wholly in the anterior 
end of the body. The 
eggsare small, ca. 0.2 mm 
in diameter, which might 
indicate that this species 
may have pelagic larvæ. 
The developraent of the wheels has been described by Den dy 
(1897); it is, indeed, very easy to find all the different develop- 
mental stages scattered among the fully formed wheels. Also de- 
velopmental stages of the sigmata occur in considerable numbers, 
so that it is very easy to trate them from the first simple, straight 
spicule with a slight median thickening, through the beginning cur- 
vature to the fully formed hook (Fig. 61).^ 
Regarding Dendy’s Chiridota geminifera I agree with Clark 
(1921. p. 165) that the evidence available is altogether too insuffi¬ 
cient for accepting this form as a separate species (or even belong- 
ing to another genus than Trochodota, as it would, evidently, 
if it should definitely prove to be provided only with sigmoid spi- 
cules, lacking completely the wheels). Until further material is at 
hånd it is the safest course to regard it as, probably, only a synonym 
of Tr. dunedinensis. 
Den dy (Op. cit. 1896) suggested that the Chiridota australiana 
Stimpson recorded by Théel (“Challenger”. Holoth. II. p. 16) as 
doubtfully from New Zealand might probably be identical with Tr. 
dunedinensis. Ludwig, however, has shown definitely (1898. Holoth. 
y A similar series of developmental stages was figured and described by 
Ludwig for Tæniogyrus (Chiridota) contortus and Trochodota purpurea 
(Holoth. Hamburger Magalh. Sammelreise, 1898; p. 79 . Taf 111 o,- n 85 
Taf. 111 . 45 .). ‘ ■ 
