93 CLASS I.— ORDER IL 



GELATINOUS. 



8. Laomedea gelatinosa. Cells campanulated ; 

 border elegantly crenated ; branches, both principal 

 and secondary, numerous and dispersed. 



Coast of Belgium. 



PRICKLY. 



9. Laoemkda muricata. Stem articulated; cells 

 peduncled, alternate and solitary on each articula- 

 tion ; ovaria peduncled, prickly, and placed on the 

 tubes of the root. 



Coast of Scotland. 



THOA. 



Plant-like and branching ; stem formed of nume- 

 rous interwoven tubes ; cells few ; ovaria irregularly 

 oval ; polypi projecting. 



These Polypidoms have characters peculiar to them,, 

 but also many irregularities, principally among those 

 which are come to their full growth ; in this last state 

 they resemble a root of a stiff and horny substance, 

 brittle in the lower part, a little flexible in the upper^ 

 and garnished with a large quantity of straight, short,, 

 stiff fibres. 



The substance of the Thoas is horny, membranous^ 

 and rather brittle. 



Their colour is a fawn, more or less deep, some- 

 times dull, at others bright and shining. 



They seldom rise beyond two decimetres, and ad- 



