178 DISTRIBUTION OF BRITISH ECHINODERMS. 



(2) Incompletely known. 



1. Cucumnria fucicola. 



2. andrewsi. 



3. Thy one flexus. 



4. elegans. 



5. Colochirus andersoni. 



(3) Deep-water forms. 



1. Stichopus tizardi. 



2. Holothuria aspera (single specimen). 



3. Astropecten sphenoplax (diagnosed in 1892). 



4. Bathybiaster vexillifer (single specimen). 



5. Pentagonaster greeni (single specimen). 



6. Mimaster tizardi. 



7. JRhegaster murrayi. 



8. Cheilaster fim briatus. 



9. Lasiaster villosus. 



10. Pt er aster per sonatus (described in 1891). 



11. Hymenaster giganteus (described in 1891). 



12. Odinia pandina. 



13. Ophiochiton ternispinis. 



14. Ophiobyrsa hystricis. 



15. Ophiomyxa serpentaria. 



16. Cidaris purpurata. 



17. gracilis ("probably immature" ; described in 1891). 



Of the third category it may be confidently predicted that some 

 of the species will be found to be synonyms of others already 

 described, and that the range of most will be extended by future 

 dredgings in deep water. 



Table III. — List of British Echinoderms, arranged by grades of 

 Depth from above dowmvards. 



Not known Number 



beyond of Species. 



10 fins. Stronyylocentrotus lividus r 1 



20 fms. Holothuria nigra, Ophiocnida brachiata 2 



30 fms. Synapta buski, Cucumaria planci, Palmipes placenta 3 



40 fms. Asterina gibbosa, Sphcerechinus granulans 2 



50 fms. Cucumaria pentactes, C. lactea, Amphiura securigera, 



Ophiopsila annulosa, Echinus miliaris 5 



60 fms. Ophiothrix fragilis 1 



70 fms. Phyllophorus pellucidus, Asterias glacialis, A. murrayi . . 3 



80 fms. Synapta digitata, Thyonefusus, Phyllophorus drummondi . 3 

 90 fms. Luidia ciliaris, Ophiocoma nigra, Echinocardium cor- 



datum ° 



100 fms. Synapta inharens, Antedon bifida, A. petasm, Ophiura 



ciliaris 4 



