MONOGRAPH OF THE EXISTING CKINOIDS. 659 



At Challenger Stations 186, 187, and 190 (the last probably the station referred 

 to by von Willemoes-Suhm) tlie large species of Zygometra, Z. microdiscus^ or 

 Z. elegans, were taken, while at the last in addition to Zygometra only Hotiialo- 

 metra dentieulata was found. These species of Zygometra occur black and white, 

 while so far as we know Comatula rotalaria and C. solains, in common with all 

 the species in the subfamily to which they belong, are always iinicolor, red to 

 brown, deep purple or black, with the dorsal side of the arms sometimes lighter. 

 Apparently' the station to which von Willemoes-Suhm referred was Station 190, in 

 49 fathoms — a depth beyond the known bathymetric range of Comatula rotalarla 

 and of C. Solaris. 



MTZOSTOMUM LONGIPES VON GRAFF. 



Occurrence. — Free-living. 

 Host. — Uncertain. 



Locality. — Blake Station 269, off St. Vincent, West Indies, 124 fathoms. 



MTZOSTOMUM CHINESICUM VON GRAFF. 



Occui^ence. — Free-living. 



Host. — Uncertain. 



Locality. — Dredged in the China Sea. 



MTZOSTOMUM LABIATUM VON GR.\rF. 



Occurrence. — Free-living. 

 Host. — Probably Fachylo metra incequalis. 



Locality. — Near Kandavu, Fiji (lat. about 19^ 00' S., long, about 178= 18' E.). 

 210, 225, or 610 fathoms. 



MTZOSTOMUM ECHINUS VON GRAFF. 



Occu)~rence. — Free-living. 



Hosts. — Comanthus parvicirra and probably Paehylometra ina'qualis or Ghari- 

 tometra incisa. 



Localities. — Challenger Station 174, near Kandavu, Fiji (latitude about 19° 06' 

 S., longitude about 178° 18' E.), 210, 225, or 610 fathoms; and between Swatow 

 and Formosa (Taiwan) (lat. 23° 20' N., long. 118° 30' E.), 17 fathoms. 



Be?narks. — Comanthus jyarvicirra is an exclusively littoral type, while both 

 Pachylometra inwqualis and Charitometra incisa are from deep water. AVith the 

 two last there were recorded from Challenger Station 174 Comatella stelligera, 

 Comaster nova>gm7iece, Comanthi/s parvicirra, SfepJuinometra spicata, and Lampro- 

 metra protectus, all littoral species which certainly did not occur with them in life. 

 It is most likely that My.zostomum echinus from Station 174 lived on one of these. 



MTZOSTOMUM ALATUM VON GRAFF. 



Occw'rence. — Free-living. 



Hosts. — Leptometra celtica and L. phalnngiwn. 



Localities. — The Minch; The Minch, 60-80 fathoms; off Loch Scavaig, Skye; 

 Porcupine Station 13, 1870, off Cape Mondego, Portugal (lat. 40° 16' N., long. 

 9° 37' AV.), 220 fathoms; off Carthagena, Spain, 80 fathoms. 



