OPHIUROIDEA 233 



end of arm, but usually small and very inconspicuous beyond 

 the proximal ones. 



The very numerous species formerly referred to the genus 

 Ophiura, or Ophioglypha, have now been separated into a number 

 of minor genera, as Amphiophiura, Homalophiura, Aspidophiura, 

 etc., but even as now restricted the genus Ophiura contains a 

 large number of species, and, evidently, needs a further sub- 

 division. In fact two minor genera have already been proposed, 

 namely Ophioglyphina Ludwig (Syn. Ophiozea A. H. Clark), with 

 0. rohusta Ayres as type species, and Dicienophiura H. L. Clark, 

 with 0. carnea M. Sars as type species. Until a complete revision 

 of the genus Ophiura has been undertaken it may, however, be 

 preferable not to adopt these two genera or subgenera. 



The biology of the various species would seem to be in the 

 main alike. They are found on both hard (sandy) and on soft, 

 muddy bottom, not buried in the ground, but moving freely about 

 by means of their arms, as described above, p. 149. Their food 

 they take by placing themselves directly above it, or they twist 

 the end of an arm around it and thus carry it to the mouth. 

 They eat all sorts of minor organisms, worms, crustaceans, 

 molluscs, echinoderms, but also detritus forms an important part 

 of their food, conveyed to the stomach by ciliary currents. As 

 food for fishes they are of some importance ; thus, e.g. Ophiura 

 texturata and albida are eaten by haddock and dab. 



Two of the species, O. texturata and albida, are known to have 

 pelagic larvae of the typical Ophiopluteus form ; very probably 

 this will be the case also with several more, at least of the littoral 

 species ; some of them, however, appear to have a shortened 

 development, with a more or less rudimentary larva (0. affinis 

 and, probably, 0. Grubei). 



Eight species of this genus are known to occur in the British 

 seas, but several others are more or less likely to occur there 

 also, namely : 0. clemens (Koehler) {^jn. Ophioglypha clemens 

 Koehler), found off Cape Finisterre, 1916 m. (" Talisman "), 

 known elsewhere from the Malay Archipelago and the Philippine 

 seas, ca. 700-1633 m. (" Siboga ", " Albatross ") ; 0. concreta 

 (Koehler) (Syn. Ophioglypha concreta Koehler), found 45° 26' N., 

 25° 45' W., 3120 m. {" Michael Sars ''), off the Azores, 2995 m. 

 (" Talisman "), and off the Cape Verde Islands, 2478 m. 

 (" Princesse Alice ") ; 0. flagellata (Lyman) (Syn. Ophioglypha 

 flagellata Lyman, Gymnophiura ccerulescens Ltk. and Mrtsn.), 

 taken off the African coast, between the Canaries and Cape Verde, 

 932-2330 m. (" Talisman "), known elsewhere from the Indo- 



