544 ZOOPHYTA. SERTULARIAD^. Dynamena- 



subdivided and panicled ; cells subcylindrical, obliquely trun- 

 cated, and rather close to the stem. 



Sea cypress, Ellis, Cor. 7 — Sertularia cup. Linn. Syst. i. 1308. Pall. 



El. 141. Lamour. Cor. Flex. 192— Common on oyster-beds. 



Height upwards of a foot ; subordinate branches twice or thrice divided ; 



the cells are short, subopposite ; the vesicles are narrow at the base, ovate, 



truncated, with a subtubular orifice, and a wing-like pointed process at each 



side. 



171. U. argentea. — Stem with alternate branches, which are 



subdivided and panicled ; cells conical, diverging, pointed. 



Squirrel's tail, Ellis, Cor. 6. t. ii. f. 4 — Sertularia cupressina, var. arg. 

 Linn. Syst. i. 1308. Pall. El. 141 — Sert. arg. Lamour. Cor. Flex. 192. 

 — Common on oyster-beds. 



Height upwards of a foot ; branches sometimes thin and bifarious, or close 

 and panicled ; cells subopposite, diverging ; vesicles oval ; nearly related to 

 the preceding, of which, by many, it is supposed to be a variety. 



172. D. operculata. — Dichotomously branched, divisions dis- 

 tant ; cells opposite, inversely conical, truncated. 



Sea-hair, Ellis, Cor. 8. t. iii. f. 6 — Sertularia op. Linn. Syst. i. 1307.— S. 

 usneoides. Pall. El. 152. — Dynamena op. Lamour. Cor. Flex. 176. — 

 Common about low water-mark, on fuci. 

 Height two or three inches ; growth usually in tufts ; cells pointed exter- 

 nally ; vesicles ovate, narrow at the base, rounded at the summit, with a short 

 tubular operculated centre. 



173. D. pumila. — Irregularly branched bifariously ; cells op- 

 posite, subcylindrical, diverging and free towards the aperture, 

 which is blunt and emarginate. 



Sea oak coralline, Ellis, Cor. J. t. v. f. 8.— Sertularia pum. Linn. Syst. i. 



1306. Pall. El. 130 Dynamena pum. Lamour. Cor. Flex. 179.— On 



Fucus serratus, common. 

 Height about an inch ; growth tufted ; each ceU seems jointed towards the 

 base ; vesicles subglobular, with a narrow foot-stalk, and a slightly contracted 

 truncated summit. 



174. D. rosacea. — Thinly branched bifariously ; cells oppo- 

 site, cylindrical, and spreading. 



Lily coralline, Ellis, Cor. 8. t. iv. f. 8 — Sertularia ros. Linn. Syst. i. 1306. 



S. nigellastrum. Pall. El. 129 Dynamena ros. Lamour. Cor. Flex. 178. 



On old shells beyond low water-mark. 

 Height two or three inches ; branches few ; cells, where united with the 

 stem, becoming tubular and narrow, suddenly diverging nearly at right 

 angles, and slightly truncated at the extremity ; the vesicles are subcylindri- 

 cal, slightly enlarged at the summit, with several spinous processes. 



175. 'D.Jilicula. — Dichotomously branched, with a cell in the 

 angle; branches short; cells opposite, oval, diverging, with a 

 tubular orifice. 



Sertularia fil. Sol. Ellis, Zooph. 37. t. vi. f. c Lamour. Cor. Flex. 188 — 

 On the stems of fuci, about low water-mark; not common. 

 Height about an inch ; branches alternate ; cells wide at the base, contract- 

 ed towards the orifice, which is slightly tubular, with a wrinkle or depression 



