Actinia viduata. 83 



spicula, of a thicker and more slender sort, may be detected 

 in abundance, with the microscope. The animal appears to 

 be subject to very little variety, but occasionally specimens 

 occur streaked with lines of a fine bluish or green colour, 

 which are sometimes interrupted or broken into spots. Very 

 young specimens have only a single circle of tentacula, which 

 are proportionally longer than they are in the adult. 



30. Acti'nia vidua'ta. (Jig. 13.) 

 Synonymes. — Actinia viduata Mull., Zool. Dan. pr. p. 231. no. 2799.; 

 Zool. Dan. t. 63. fig. 6, 7, 8., copied into the Encyclop. Method, tab. 72. 

 fig. 4, 5.; Turt. y Lin., iv. 101. 



The body, when contracted, forms a very depressed cone : 



when relaxed or expanded, it is cylindraceous, about half an 



13 an inch in diameter, and 



vaceous, prettily annul ated 

 Actfniavidukta. w j tn wn it e , with a darker 



ring at the base, and the oral disc is mottled or striated with 

 pale lines. 



This may be, as I long believed it was, an immature state 

 or variety of the preceding; but I have lately discovered some 

 peculiarity in its habits which induces me to consider it dis- 

 tinct. Actinia mesembry anthem um is always exposed, and 

 very cleanly in its person, never allowing its glossy coat to be 

 soiled by mud or other extraneous matter ; but A. viduata 

 buries itself in the sand, and lies very snugly concealed. 

 Attaching itself to shelving rocks which are covered with 

 compact sand for about an inch in depth, it burrows in the 

 same, leaving a small aperture opposite the mouth, through 

 which the tentacula are displayed when the tide flows. At 

 ebb nothing of the animal can be seen, and the holes in the 

 sand scarcely betray it, for they are exactly similar to those 

 of most arenicolous worms. 



Berwick upon Tweed, Nov. 10. 1834. 



G 2 



