CRINOIDEA 



31 



M-ith Fig. ISg). Pinnulei with ca. 30 segments. Distal edge of 

 brachials not thickened and prominent (Fig. I32). Pinnule joints 

 very gradually decreasing in size, none of the proximal joints 

 with prominent spines at outer edge. Genital organ extending 

 beyond basal half of the pinnule. Colour in life very variable, 

 yellow or red-brownish, or a deep 

 purple, to nearly white ; often very 

 conspicuously banded. 



The eggs are not attached in 

 clusters to the pinnules, but 

 dropped free into the water. The 

 larva leaves the spiny egg mem- 

 brane uniformly ciliated, the cili- 

 ated bands only appearing later. 

 The Pentacrinoid (Fig. 17) is some- 

 what coarser than that' of A. 

 bifida ; the stalk has ca. 25 seg- 

 ments. Only the younger stages 

 of this Pentacrinoid are known, 

 and only very few specimens have 

 been found ; the longer swimming 

 period of the larva accounts for 

 the fact that the Pentacrinoids are 

 found very scattered, attached to 

 algae, Hydroids, etc. 



Two species of Mijzostoma occur 

 on this Comatulid, viz. M. cirri- 

 ferum Leuckart and 21. jyarasiticum 

 Leuckart. Also a species of Loxo- 

 soma occurs on its pinnules. 



In British seas this species is 

 known with certainty from off S.W. 

 Ireland and the Orkney Islands. 

 It is therefore almost certain that 

 it will prove to occur all along the 

 west coasts of Great Britain ; very probably it will be found to 

 occur also some way down the North Sea coasts. Elsewhere it 

 occurs at the Faroe Islands, Iceland, and the Scandinavian 

 coasts as far north as Tromso. Bathy metrical distribution, 

 ca. 20-325 m. 



As this is a more northern species than A. bifida it is to be ex- 

 pected that in the more southern parts of its range it will be found 

 mainly in the deeper and colder Avaters, while the more southern 



Fig. 17. — Pentacrinoids of Ante- 

 don petasus. In the larger 

 specimen nine stalk - joints 

 have been omitted. The 

 smaller specimen x 40, the 

 larger x 20. a, Anal plate ; 

 ax, Axillary; b, Basal; o, Oral; 

 r, Radial plates. (From Dan- 

 mark's Fauna.) 



