316 NATURAL HISTORY OP 



Sertularia puStnlosa {E. and 8., Fleming, &c.),Vesi- 

 cularia pustulosa [Thom-pson), Valkeria pustulosa {G. /., 

 P.H.O.,D.L.). 



Hab. : Isle of Wight (Ellis), Ilfracombe, Salcombe 

 [T. H.), Menai Straits, Jersey {A. 8. P.), Cornwall 

 (0. W. P.). 



This is the " Dichotomous Tubular Coralline " of Ellis 

 (Coral. 54) . The stem is slender, jointed, and branched 

 dichotomously, of a light horn colour. The zooecia 

 are arranged in groups (one group to each internode), 

 and are subspirally arranged on the stem in two series. 



The colony attains a height of 2 — 3 inches. The 

 polypide has eight tentacles. 



4. B. ciTRiNA, Rincks. 

 Valkeria citrina {T. H.). 

 Hab. : Ilfracombe (T. H.). 



Distinguished from the preceding by its more slender 

 habit, and by having " a bright line of citron-coloured 

 granules traversing each tentacle, and running down 

 the body, probably marking the course of the oeso- 

 phagus." 



5. B. GRACILLIMA, Hificks. 



Valkeria gracillima (T. H.). 



Hab. : Devon and Cornwall (T. B".). 



The zocecia are disposed in small groups at intervals 

 along a creeping stem. They are larger than in the 

 two preceding species, and are flask-shaped. 



Genus IV. Avenella, Balyell. [Avena, oats.) 

 Zooecia solitary, irregularly scattered, subunilateral, 

 curved, and slightly contracted above. Stem repent, 

 nearly simple. Polypides with numerous tentacles, 

 and a small gizzard. — T. H. 



