484 Mr. A. H. Hassall's Description of 



their nature is, that they are organs destined to contain the 

 ova until they have arrived at a certain degree of maturity, in 

 fact, ovaries, and if not ovaries, the ova themselves in a very 

 early stage of their formation. 



I have been induced to raise this species to a generic rank, 

 principally from the arrangement of the ova in circles, which 

 is, I believe, peculiar to it. Some weeks ago, when at Belfast, 

 Mr. Thompson pointed out this species to my notice, say- 

 ing, at the same time, that he had forwarded it long since 

 to Dr. Johnston as new ; its distinctive characters had how- 

 ever been made out by myself long previous to this interview 

 with Mr. Thompson, and reference is made to it in my Catar 

 logue*. 



This zoophyte, as well as the succeeding species, exhibits in a 

 very remarkable degree that ^^ close adhesion to life,'^ the usual 

 accompaniment of a low organization, which renders this class 

 of animals so patient of injuries which would be fatal to 

 beings of greater complexity of structure. I have on more 

 than one occasion seen the polypidoms of this and the follow- 

 ing species enveloped in a firm coating of ice ; on immersion 

 of either of these in sea-water the coating has become dis- 

 solved, and the polypi have protruded their feelers, and have 

 appeared as active as though they had never been exposed to 

 such a very low degree of temperature as would have de- 

 stroyed the life of more highly organized animals. From this 

 it is apparent that their sensibility cannot be very great. 



Dublin bay, on Fucus serratus ; not uncommon. 



We now come to the description of the second genus. 

 Order ZOOPHYTA ASCIDIOIDA. 

 Family Alcyonidul^. 

 Genus Sarcochitum. 

 Character. — Polypidom encrusting, fleshy, covered with numerous 

 prominences of irregular form and unequal size, from which the po- 

 lypi issue ; ova circular, scattered singly throughout the polypidom ; 

 a dark brown body of a circular form filled with small round granules 

 is apparent in great numbers through the polypidom. — Polypi asci- 

 dian. 



Sarcochitum poly oum. — Polypi with twenty tentacula. 



This species is also usually found investing Fucus serratus, 

 the frond of which it sometimes covers to the extent of several 

 inches. The crust is thin and fleshy, and covered with nu- 

 merous large eminences of irregular form and unequal size, 

 which exhibit a puckered appearance in the centre, and from 



* Published in the 'Annals' for Nov. 1840, p. 170. 



