BELONGING ÏO THE GENERA FILIGELLA AND ACIS. Ö 



right to be retained and the name Elasmogorgia may well be dropped. 

 After my study, the diagnosis of the genus may be modified 

 as follows : 



Colony flexible, filiform, simple or slightly branched, free 

 or fixed ; distal end truncated, slightly swollen ; proximal end 

 rounded and either free or with disc for attachment ; axis horny ; 

 cœnenchyma thin, formed of small w^arty spindles ; polyp-cells 

 subalteruate or irregularly disposed ; anthocodia with operculum^^ 

 composed of a number of very slender spicules transversely ar- 

 ranged at tentacle-base and arranged en chevron on the aboral 

 side of tentacles, wholly retractile into low conical verrucœ provided 

 with spicules resembling those of general cœnenchyma. 



AclS DUCHASSAING & MiCHELOTTI. 



Acis DucH. & Mich., Mém. corail., 1860, p. 19. 



Ada Doch. & Mich., Supplem. Mém., 1864, p. 14. 



Acis KÖLL., Icônes Histologicae, 1864, p. 136. 



Acis RiDL., Ann. Mag. Nat. Hist., (5) X., 1882, p. 126. 



Acis Stud., Arch. Naturgesch., 53, I, 1887, p. D'à. 



Acis Wr. & St., Challenger Report, 1889, p. lvi and p. 121. 



Acis pustulata We. & St. 



Acis pustulaia Wk. & St., Challenger Report, 1889, p. 122. 

 (PI. I., fig. 2 ; PI. IL, figs. 10-12). 



Several specimens of a Muriceid coral have come into my 

 possession, which I do not hesitate to identify with Acis puslulata. 



1) Whether tlie type species also had an operculum of the same construction cannot be 

 decided, as the specimen of it was lost. 



