216 NORMAM, ON BARE BRITISH POLYZOA. 



vibracular capsules of S. scruposa are narrow and erect, with 

 the opening extending perpendicularly downwards. 



HiPPOTHOA EXPANSA, 11. sp. PI. VI, figS. 1, 2. 



Polysoary adherent, branched, spreading, calcareous and 

 semitrans'parent. Cells oblong-ovate, ribbed transversely, 

 and very minutely striated longitudinally, tapering below 

 into a tubular stem ; aperture terminal at the upper end, 

 rather small and rounded, with a sinus below, the rim thin 

 and a little elevated. The cells and connecting tubes are 

 bordered by a thin calcareous expansion, through which the 

 tubes run, those of each branch arising from the side of a 

 cell at a very slight angle, the branches occasionally anasto- 

 mosing. Length of cells about one twentieth of an inch, 

 expansion of polyzoary from a quarter to half an inch. 



Dredged in 100 fathoms off Unst, Shetland, in 1864, by 

 Messrs. Jeffreys and Peach. 



The specimen from which this description is taken is upon 

 an old shell of Pecten Islandicus, a species which has not 

 been found recent on our coast. There are also adhering to 

 the same shell a Spirorbis and a Lepralia {ventricosa) , which 

 are common in the same seas at the present time, and an 

 unknown Cellepora, apparently subfossil. The Hippothoa, 

 however, is quite fresh, preserving a gloss and transparency 

 which leave little doubt of its being a recent species. This, 

 the only known specimen, is now, with the rest of the collec- 

 tion of the late Mr. Alder, in the Museum at Newcastle- 

 upon-Tyne. 



^TEA siCA, Couch. 



Hippothoa sica, Couch. Corn. Fauna, iii, p. 102, pi. xix, 



fig. 8 ; Johnston, British Zoophytes, 

 2nd edition, p. 292. 



^tea recta, Hincks. Catalogue of Zoophytes Devon and 

 Cornwall, p. 35, pi. vii, fig. 3. 



— anguina, (5, forma recta, Sniitt. Ofversigt af K. Vet. 



Akad. Foih., p. 281, pi. 

 xvi, figs. 5, 6. 



This species is probably distributed all round our coasts, 

 as I have procured it from the following localities: — Guernsey, 

 Clornwall, Antrim, West of Scotland, and Shetland. Sniitt 

 finds it in Scandinavia. 



