Actinia. Z. HELIANTHOIDA 219 



When expaiuled, the superior division of the body seems formed 

 of fleshy bars placed in a reticulated manner, and lined with a fine 

 membrane. From perforated warts, placed without order on the outer 

 coat, issued white filameutose substances variously twisted together : 

 I have observed a similar body ejected from the mouths of all the 

 species of this genus which have fallen within my notice." Adams. 



The following- more detailed description of this very interesting 



species is by Dr Coldstream. " General mass of the animal flattened 

 and extended ; thickness at the oral disc three-tenths of an inch, di- 

 minishing towards the circumference of the base ; longest diameter 

 of the base about three inches ; margin minutely crenated ; colour of 

 the body, near the base, reddish brown, passing gradually into a light 

 cream colour towards the oral disc ; whole surface striated longitudi- 

 nally with alternate opaque white, and translucent bluish lines, and 

 marked irregularly with bright reddish-purple spots. These spots 

 are confined to the outer coat, which is easily peeled off". That be- 

 low it is of a pink colour, and is marked with the strise, which shine 

 through the outer coat. Oral disc of an elongated oval form, white, 

 and bearing on its outer margin numerous rather short tentacula ar- 

 ranged in three or four irregular rows : tentacula shorter than the 

 body, acuminated, white, each marked with a faint streak of brown ; 

 mouth large, oval ; lips white, contracted into folds ; internal sur- 

 face of the stomach marked with numerous white strise. Base 

 fixed to a thin horny expansion attached to the apertures of va- 

 rious dead shells, such as Trochus cinerarius and T. Magus, and form- 

 ing, as it were, an extension of the body- whorl of the shell in a spir- 

 al form. Over this, the Actinea is spread entirely, and covers also 

 more or less of the shell. Its oral disc is uniformly situated close to 

 the inner lips of the horny case. The aperture of the case is accu- 

 rately surrounded by its body, the margins of the opposite sides of 

 which meet, and are closely applied to one another at the middle of 

 the outer lip of the aperture, whence they run upwards towards the 

 old shell, where they generally separate again, leaving its apex un- 

 covered." " The horny membrane to which the Actinia is 



attached, covers, for the most part, nearly the whole of the external 

 surface of the ,old shell to which it is fixed, and from the circumfe- 

 rence of its aperture, is prolonged into a large hollow expansion, re- 

 sembhng in form, and occupying, relatively to the shell, the place of, 

 a ventricose body-whorl. Its substance is of a uniform thickness 

 throughout its whole extent, of a greenish-brown colour, translucent, 

 having both surfaces irregularly wrinkled transversely. In a recent 

 state it is quite flexible, but when dried it is brittle. It takes fire 

 and burns readily, leaving a very small residuum, which does not ef- 



