SEETULARIAD^E : SERTULARIA. 67 



The polypiferous shoots originate from a slender tubular thread 

 which creeps along the surface of the fucus, and connects them all 

 together. The shoots are very numerous, often covering a consider- 

 able space of the sea-weed, seldom more than half an inch in height, 

 of a dusky horn colour, and thickish texture, sparingly branched, 

 filiform, flattish, serrated with the cells, which are divided usually into 

 pairs by a dissepiment or joint, but sometimes there are four cells 

 between the constricted separations. The polypes have 14 tentacula, 

 and when the animal displays them, it at the same time extrudes 

 the body far beyond the rim of the cell.* The vesicles are copiously 

 produced during the summer months, and are irregularly distributed 

 over the branches : they are subsessile, ovate with a short tubulous 

 rim, smooth, or sometimes wrinkled circularly : in the centre a 

 placentular column is at seasons obvious, and in June I have found 

 them filled with innumerable pellucid granules floating in an am- 

 niotic liquor. 



Mr. C. W. Peach has sent me a very pretty and delicate variety, 

 which he finds on the coast of Cornwall and of Norfolk. It appears 

 to owe its delicacy to the circumstance of growing in deep water. 

 Mr. W. Thompson sends another variety (dredged in Dublin bay by 

 W. H. Harvey), which imitates the early state of S. argentea. It 

 has a flexuous percurrent rachis with numerous erecto-patent 

 branchlets, which seem to be mostly opposite at their insertions. 

 The cells are smaller than usual, and more remote, but do not offer 

 any other peculiarity. 



5. S. EVANSII, " has opposite branches, and short denticles 

 placed opposite to each other ; the ovaries are lobated, and arise 

 from opposite branches, which proceed from the creeping ad- 

 hering tube.' 1 ' 1 Mr. John Evans.-}- 



Sertularia Evansii, Ellis and Soland. Zooph. 58. Lam. Anim. s. Vert. 2de edit ii. 

 154. Dynamena Evansii, Lamour. Cor. Flex. 177- Flem. Brit. Anim. 545. 



Hab. " Among some sea productions brought from Yarmouth, in 

 Norfolk, in the year 1767." Ellis. 



11 This coralline is about two inches high, very slender, and of a 



" The number of tentacula in this species is not very constant, but usually 

 about 16." A. H. Hassatt. 



t Ellis calls him " a sea-officer in the East India Company's service." Probably 

 the same Mr. Evans, a surgeon, whom Petiver mentions amongst the contributors to 

 his museum. 



F2 



