78. i 



80. 



BRITISH MARINE GENERA 533 



Main stem zigzag. Branchlets delicate, many ending in sharp points. 



Zooecia small, ovoid . . . Vesicularia spinosa 



Axis jointed. Zooecia small, in small clusters. Polypide without a 



gizzard .... Valkeria uva, var. cnscuta 

 Zooecia in whorls, attached to the axis by thread-like stalks, much 



longer than themselves . . . Hippuraria egertoni 



Zooecia pear-shaped, produced at the lower end into a distinct stalk. 



Gizzard absent . . . . . .80 



Zooecia not distinctly stalked, although sometimes constricted at the 



base . . . . . . .81 



Stalk long. Zooecium movable on its stalk, compressed, with a 



membranous area on one side. Twelve or more tentacles. 



Usually found on Crustacea . . . Triticellti 



Stalk variable. Zooecium very transparent ; orifice bilabiate. Ten 



to sixteen tentacles . . . Farrella repens 



Zooecium very small, much elongated and narrow. Eight tentacles. 



Valkeria tremula 

 (See also Arachnidium, No. 73). 

 f Zooecia short, minute, with a few short spines on each side of its 

 81. -I broadened base. Upper end tubular . Buskia nitens 



\ Zooecia elongated . . . . . .82 



( Zooecia transparent . . . . . .84 



' \ Zooecia brown, often quite opaque . . . .83 



{Zooecia large (about -^ inch long), distant, constricted at the base, 

 bearing scattered bristles. Usually found on Crabs or Hydroids. 

 Awnella fusca 

 Zooecia tall, cylindrical, not constricted at the base . Cylindroecium 

 ( Zooecia minute. Axis dilating at intervals into swellings, from 

 which new zooecia originate. These may give rise to new stolons, 



84. X or directly to new zooecia. No gizzard. Found in brackish or 



fresh water .... Victorella pavula 



\ Axis not dilated, as above . . . . .85 



( Zooecia small, in small groups. No gizzard . . Valkeria uva 



85. -! Zooecia long, scattered or in groups. Gizzard present. 



Bowerbankia (creeping forms) 



It is highly probable that the Ctenostome genus Hypophorella l 

 will before long be added to the British Fauna. The animal 

 consists of delicate stolons, which give off small zooecia at 

 intervals ; and it is known to excavate passages in the substance 

 of the tubes of certain Polychaet worms (Chaetopterus and 

 Lanice). 



1 See Arch. Zool. Exp. 2 ser. vi. 1888, p. 135 (as Delagia), aud ibid. x. 1892. 

 p. 594. 



