344 BULLETIN OF THE BUREAU OF FISHERIES. 



of his monograph on American Hydroids. This family is the Hebellidae. The reasons 

 for adopting the name are given in the text where the family appears in the regular 

 course of the paper. In the synonymy, reference to the original description is always 

 given, together with references to some of the well-known papers in which a description 

 of the species appears. In no case is the author's name given with the family or genus, 

 but the characteristics of each, as significant of what it means in this paper, is always 

 given. 



KEY TO THE HYDROID FAMILIES FOUND IN THE BEAUFORT REGION. 



A. Gymnoblastea. 



a. Hydranths with scattered filiform tentacles Turrids. 



b. Hydranths with one whorl (or two whorls closely approximated) of filiform 



tentacles around the base of the proboscis. 



I. Proboscis conical or clavate. 



1. Colony regularly branched Bougainvillidae. 



2. Colony not branched, with basal encrusting coenosarc Hydractinidae. 



II. Proboscis trumpet-shaped or hemispherical Eudendridae. 



c. Hydranths with scattered capitate tentacles but no filiform tentacles Syncorynidae. 



d. Hydranths with a single row of filiform tentacles around the base and 



capitate tentacles scattered over the proboscis Pennaridfe. 



B. Calyptoblastea: 



a. Hydranths with trumpet-shaped proboscis and campanulatehydrothecae. . . .Campanularidse. 

 6. Hydranths with conical proboscis and tubular or turbinate hydrothecae. 



I. Hydrothecse with operculum of converging segments Campanulinidae. 



II. Hydrothecae without operculum. 



1. Stem fascicled, gonosome a Coppinia mass. Lafoeidae. 



2. Stem simple, gonangia not collected into a mass Hebellidse. 



c. Hydrothecae reduced to saucer-shaped hydrophores Halecidae. 



d. Hydrothecae sessile, adnate to main stem or branches. 



I. Hydrothecae arranged on both sides of branches Sertularidae. 



II. Hydrothecae on one side only of the branches Plumularidae. 



Suborder GYMNOBLASTEA. 



Hydroids with hydranths unprotected by hydrothecae and gonophores unprotected by gonangia. 



Family TURRID.C 



Trophosome. — Hydranths with scattered filiform tentacles. Colony simple or branched. 

 Gonosome. — Gonophores give rise to free medusae with simple radiating canals and simple marginal 

 tentacles. 



Genus TDRRITOPSIS. 



Trophosome. — Small colonies with few branches from a much branched stolon. Perisarc reaching 

 to the base of the hydranth . 



Gonosome. — Gonophores give rise to medusae with four radial canals and several simple marginal 

 tentacles. 



