114 Z. HYDROIDA. Tubularia. 



Flex. 230. Corall. 100. Cuv. Reg. Anim. iii. 299. Bosc, Vers, iii. 89, 

 pi. 28, fig. 3. Fkm. Brit. Anim. 552. Johnston in Trans. Newc. Soc. 

 ii. 252. Dalyell in Edin. New Pbil. Journ. xvii. 411 ; and xxi, 93; 

 and in RejJ. Brit. Assoc, an. 1834, 600. Lister in Pliil. Trans, an. 1834, 



366, pi. 8, fig. I Tub. calamaris. Pall. Elench. 81 Tub. gigan- 



tea, Lamour. Soland. 17, tab. 68, fig. 5 Tub. gracilis? Harvey in 



Proc. Zool. Soc. no. 41, p. 54 La Tubulaire ehalumeau, Blainv. 



Actinolog. 470. 



Hub. On shells and stones from deep water. Leith shore ; Ork- 

 ney and Shetland Islands, Professor Jameson. Scarborough, Mr 

 Bean. Coast off Dunstanborough Castle, 31r R. Emhleton. Cul- 

 lercoats, Northumberland, 3Ir J. Alder. Berwick Bay. 



The tubes are simple or sometimes divided once at the base, where 

 they are twisted and flexuous, fistular, even, continuous or sometimes 

 wrinkled at distant intervals with a few annulations, horn-coloured, 

 from 6 to 12 inches in height, and about a line in diameter. Ellis's 

 comparison of them to " part of an oat-straw, with the joints cut oiF," 

 is very apt. They are filled with a soft almost fluid reddish-pink pulp 

 in organic connection with the Polypes, which project from the open 

 ends of the tubes, and are not retractile within them. The body, or 

 naked portion, of the polype forms a globular knob of a scarlet colour, 

 produced above into a sort of proboscis encircled with a series of nu- 

 merous short tentacula of the same colour. Around the base of this 

 body there is another circle of much long-er tentacula from 30 to 40 

 in number ; and between their insertion and the body clusters of ovi- 

 form g-emmules are produced at certain seasons. The neck of the 

 polype is greatly constricted ; and we find that the recent tube is 

 marked with several longitudinal pale lines, placed at equal distances, 

 and which are evidently caused by some structure of the interior pulp, 

 for when empty the tubes exhibit no such appearance. What is their 

 relation to the currents observed by Mr Lister? — As the animal be- 

 comes weak when kept in a basin of sea-water, the head drops off, 

 like a flower from its stalk ; and if it is immersed, even when most 

 vivacious, in fresh-water, the pulp is expelled from the tubes until 

 these are almost emptied. If this is efl"ected by a contraction of the 

 tube (and the phenomenon is not otherwise easily explained), does 

 not this imply a degree of irritability in the polypidom inconsistent 

 with the theory of its extravascular character ? 



I can find no characters either in the description or fig-ure of Tub. 

 gigantea which warrant its separation as a distinct species. The 

 character of Lamouroux is : " T. tubulis rectis, simplicissimis, ad 

 basim attenuatis, gradatim dilatatis, deinde tequali crassitie, laevibus 

 nitidisque." — Neither do I find in Mr Harvey's description of his 



