SEHTULARIA. 131 



bleached appearance, as if drifted for a considerable time. 

 We have dredged it in Lamlash Bay, but the specimens, 

 though evidently in their native locality, were not good. 



" Height nearly a foot ; stem arising from wrinkled tubes, 

 which adhere to stones or shells ; the cells are usually oppo- 

 site, sometimes alternate, and the stems seldom exhibit any 

 joints ; vesicles egg-shaped, with a narrow base and a con- 

 tracted subtubular summit." [Dr. Fleming.) Though gene- 

 rally white, or of a pale yellow colour, specimens of a reddish 

 hue are occasionally found. Those I got in Arran, and in 

 the Trith of Forth, where they are abundant, were very 

 much dotted with Spirorbis. 



Sir J. G. Dalyell has recorded many interesting observa- 

 tions made by him on this zoophyte, kept alive in jars of 

 sea-water. " It is obvious," he says, " that two differently 

 formed vesicles are borne by the S. alnetina, a fact also in- 

 cident to a few other Sertulari(^." 



He gives a description and figure of what he calls Sertu- 

 laria ahietinulay diminutive sea-fir. It bears a considerable 

 resemblance to S. ahietina, but he has been unable to iden- 

 tify the two. It is generally from one to two or perhaps 

 three inches high. He has never observed it except on old 

 shells. 



