new Species of Hydroids. 363 



irregularly and loosely brandling, the branches being slender 

 and giving rise to very long ultimate ramuli, which are often 

 many times the length of the hydranths. Proximal branches 

 with a series of distinct annulations above their origin ; distal 

 branches and ultimate ramuli with the annulations indistinct 

 or wanting. Hydranths lohite, minute, with large trumpet- 

 sliaped proboscis and 26 to 32 tentacles. 



Gonosome. — Male gonophores borne in bithalamic verticils 

 below the bases of the tentacles of the hydranths ; female 

 gonophores arranged in a somewhat irregular raonothalamic 

 verticil in the same position. The hydranths bearing gono- 

 phores are not so generally aborted as in the case of E. ca- 

 pillar e. 



Colour, — Main stem and branches distinctly dark brown, 

 fading to pale horn-colour and whitish in the ultimate ramuli. 

 Hydranths white, with little, if any, brownish or pinkish tint 

 to the body or proboscis, although the contents of the body- 

 cavity may show through and impart an effect of faint colora- 

 tion. 



Habitat. — On stones in shallow water near Millbay Channel. 

 The stones are often covered with a dense growth of this 

 hydroid, which appears to the unaided eye like white cottony 

 tufts or downy patches. The gonophores were abundant in 

 April. 



The distinguishing features of this species are the minute- 

 ness of the colony and of the individual hydranths, both of 

 which are less than half the height of any other Eudendrium 

 from British waters, and the very striking white colour of the 

 hydranths — a feature not found in any other Eudendrium in- 

 habiting those waters. 



Opercularella hispida, sp. n. (PL XIV. fig. 2.) 



Trophosome. — Hydrothecaj borne on very short pedicels 

 springing from a creeping root-stalk, almost tubular, with 

 slightly swelling sides, about three times as deep as wide. 

 Margin divided into a number (10 to 12) of long slender 

 teeth, whose points converge over the centre of the hydro- 

 theca and form, an operculum when the hydranth is retracted. 

 Hydranth cylindrical, capable of great protrusion, with a 

 conical proboscis and about 16 strongly serrated tentacles, the 

 serrated appearance being due to very large nematocysts. 



Gonosome not known. 



habitat. — Found growing over a stone, together with a 

 colony of Clava multicornis. 



Locality. — Plymouth, England. 



This species bears some resemblance to Calycella syringa^ 



