REPOET ON THE ALCYONARIA. 47 



dont le tissu est lisse ou subereux chez ces derniers, tandis qu'ici il est h^risse d'une 

 multitude de petites pointes, formees, soit par des sclerites squammiformes, soit par des 

 epines naviculaires." Dr. Gray excluded the forms with fusiform or spiniform scales, 

 and in this he has been followed by Professor Verrill, who says he would include in 

 Primnoitlaj " only those genera in which the spicules of the coenenchyma and calicles are 

 scale-like and the axis more or less calcareous at least on the main stem," thus excluding 

 Muriceidse. With this decision we agree, but the discovery of forms among the famUy 

 Isidse with scale-like spicules leaves this character no longer solely characteristic of the 

 Primnoidae, and the absence of the otherwise very diagnostic opercular scales in the new 

 genus Primnoides also excludes this otherwise fairly constant character from being one 

 of family value. 



The diagnosis of the family may be as follows : — Axis calcareous, flexible or rigid, 

 simple or branched. Polyps prominent, arranged either alternate, opposite, in spirals 

 or verticils on the axis. Coenenchyma of the axis thin, with scale-like spicules. Polyps 

 with scale-like or annular spicules. Tentacles completely retractile, in most with a series 

 of several (mostly eight) triangular scale-like spicules, closing over the tentacles and 

 forming an operculum — or the scales of the base of the tentacles of the polyp forming 

 a quasi operculum over the infolded tentacles {Primnoides). 



The family may for convenience be divided into the following four subfamilies : — 



1. Callozostroninse. — Axis flexible. Polyps prominent, with well-marked opercular 



spicules. 



2. Calyptrophorinse. — Axis rigid. Polyps prominent, with large annular body- 



spicules and with opercular spicules. 



3. Primnoinse. — Axis rigid. Polyps prominent, with scale-like spicules and with 



well-marked opercular spicules. 



4. Primnoeidinse. — Axis rigid. Polyps prominent, with scale-like spicules but 



with no opercular spicules. 



Subfamily 1. Callozostronin^. 



This subfamily is established for a deep-sea species, with a flexible, feebly calcareous 

 axis, around the greater portion of which the very prominent polyps are arranged in a 

 bilateral manner in tightly packed rows of twelve or more. The naked space of the 

 axis, caused by the divergence of the polyps, forms a narrow ridge extending along almost 

 the whole length of the axis up to the very apical region, where the polyps budding from 

 a central stolon-lLke mass are at least temporarily arranged in complete verticils. As 

 no basal portion was dredged, it is impossible to be sure whether the colony was rooted 

 or free. The spicules are scale-like. The tentacles are retractile and covered by a 

 variable number of opercular scales. 



