1869.] and Membranipora Bengalensis. 33 



The principal and characteristic distinctions of this species are, 

 the very great softness and transparency of the body, having a very 

 slight greenish tinge, mingled with somewhat of a pale fleshy colour, 

 a distinct layer of a dark green pigment being deposited near the 

 external surface, below the outer muscular layer of each alternate 

 septum, and thus producing greenish, longitudinal bands of about 

 equal width ; further, the prominent lips of the aperture, the great 

 thickness of the primary tentacles, the blueish purple colouring of 

 the ovaria, the yellowish craspeda, the purely white acontia, and their 

 great length. 



' I shall at first speak of the various normal forms of this species, 

 than of the anatomy of the different organs and of their signification, 

 and last of the physiology, the habits and modes of life. 



a. Form. 

 The general form of the body of Sag. Schilleriana is common to that 

 of other truly marine species of the same genus, the column being, 

 however, when the animal is expanded in a normal condition, a little 

 shorter than the diameter of the basis (see pi. X. fig. 1). In conse- 

 quence of the softness of the fleshy substance, the base, (which is 

 comparatively more solid than any other part), always adapts itself 

 entirely to the object on which the animal is sessile. On a smooth 

 surface, the circumference of the base is almost circular, only on 

 account of the projecting septa slightly undulating at the margin ; 

 on a rough surface all cavities* are filled 1 up with the fleshy mass, 

 securing at the same time the attachment of the body, but also alter- 

 ing the original roundish form into an oval or irregularly polygonal one. 

 The septa are distinctly traceable by the alternate greenish bands. 

 ■ There are three principal forms to be observed, which may be called 

 the normal ones, being successively adopted by every animal in a 

 healthy condition. The first is the expanded form (pi. X. fig. 1) from 

 which these animals derived their name of sea-flowers. The frequent 

 bright colouring of the disc, as a rule, increases their resemblance to 



* I have seen portions of the body filling such cavities of about half an 

 inch in depth, and one-fifth of an inch broad. When the animal was carefully- 

 detached, it lasted for several days, till all the protuberances disappeared, 

 but they were at last assimilated to the regular form of the body. 



5 



