244 



The maximum length varies greatly in the different species, e.g., uxM. gracilis, 

 Wright and Studer, 0'46 mm., in M. umbraticoides, Studer, 0-6 mm., in TV/, flexilis, 

 Hiles, 1"105 mm., in M. complwnala, Wright and Studer, 1-25 mm., in M. nitida, 

 Verrill, 2 mm., in M. arborea, n. sp., 3 "5 mm., in M. ranio.m, Thomson and 

 Henderson, 4-5 mm., and in M. imrpurea, Whitelegge, 5'5 mm. Smaller forms 

 occur in the verruca?, the inner layer of the ccenenchyma, and in the tentacular 

 operculum. In addition to these spindles tri- and quadri-radiate forms occur 

 in M. (•ras^a, Wright and Studer, and club-shaped types in the verructij of M. 

 gradlis, Wright and Studer. In M. ambratlcoides, Studer, the outer spicules 

 are very broad and have the warts developed mainly on one side and are some- 

 w^hat scale-like, while in M. arborea, n. sp., many of the spindles have a median 

 constriction and a slight swelling on either side of this. 



Geographical distribi(tion. — All the species hitherto described are Indo- 

 Pacific, thus : — 



North Pacific Ocean : {a) off Japan : M. nitida, M. complanata, M. perramosa. 

 South Pacific Ocean : {a) off Queensland : M. tenera. 



(b) Funafuti : M. jxirpurea, M. flexilis. 

 [e) Arafura Sea : M. umbraticoides, M. crassa, M. 

 tenera. 

 Indian Ocean : (</) Mauritius : M. perramosa. 



{b) Bay of Bengal : M. complanata, M. ramosa, M. rubra, 

 M. bengalensis. 



(c) Ceylon Seas : M. nitida, M. complanata, M. ramosa, 



M. rubra, M. arborea. 



(d) Persian Gulf : M. ramosa. 



Bathymetrical distributiott. — All are found in comparatively shallow water 

 except M. nitida and M. perramosa which were dredged from a depth of 345 

 fathoms. Other depths : M. umbraticoides, 49 fathoms ; M. tenera, 14-20 

 fathoms ; M. perramosa, 90 fathoms ; M. gracilis, 16-20 fathoms ; M. ramosa, 

 48-49 fathoms; M. rubra, 18 fathoms; M. bengalensis, 88 fathoms; and M. 

 arborea, 13 fathoms. 



The following abbreviated descriptions recapitulate the characters essential 

 for the identification of species. 



Muricella wnbraticoides, Studer. 



Muricea umbraticoides, Studer. " Uebersicht der Anthozoa Alcyonaria der 

 Gazelle," " Monatsber. Akad. Wiss. Berlin," Taf. III. fig. 16 a, b, 1878, p. 650. 



Muricella umbraticoides, Wright and Studer. " ' Challenger ' Report," vol. 

 xxxi. p. 124. 



Colony branched in one plane ; branches arise at almost right angles and 



