202 ZOOPHYTES. 



The planulse, from a state of activity, contracted and became motion- 

 less : being moulded into vivid yellov^' sjiots. These soon exhibited a rising 

 stalk, whereon projections denoted incipient twigs, from which hydr^ 

 were subsequently generated. I shall insist no farther on the history of 

 this species of the Sertularia, which has never occurred to me under any 

 other aspect than as a single red slender stem, with an ovate vesicle in the 

 axilla of the twig and stem, producing one large yellow planula. 



§ 2. Sertularia (Antennularia) ramosa. — This product, which is 

 either a different species or a distant variety of the preceding, affords 

 greater scope for observation. 



Adult specimens rise four, five, or six inches high, by a short, bare 

 stem, composed of aggregated tubuli. Numerous boughs and branches 

 above, diverge at a large angle from their respective principal parts, the 

 whole thickly clothed with twigs exceeding half an inch in length, and 

 sometimes bearing 14 or 15 denticles on the upper side. Owing to the 

 recurvature of the twigs outwards, many specimens present a rich plumose 

 appearance. 



The product is usually of a vivid green colour, sometimes of a yellow- 

 ish shade ; the lower parts dark, however, or of dingy orange, the higher 

 and newer tending to dingy yellow. — PI. XL. 



The hydrse are greenish, provided with 19 or 20 muricate tentacula. 

 They are lively creatures, contracting and clasping together suddenly, but 

 of delicate nature, and difficult to be preserved, which, with the tendency 

 of whole specimens to decay, should warn the naturalist not to postpone 

 his scrutiny of the parts, if expecting to find them animated. No peculi- 

 arities distinguish the hydras, except their identity with the muricate tribe. 

 The interval between the denticles or cells, is equal to the expansion of 

 the hydra.— PI. XXXIX. fig. 7. 



It has appeared to me that, from the tendency of the growth, the ex- 

 panded extremities of a luxuriant specimen might be circumscribed by 

 an elliptical outline. The specimen, Plate XL., which is to be con- 

 sidered a fine one, rose between four and five inches in height ; its diver- 



