ACTINIAD^E : ACTINIA. 21 7 



and almost black spots, not very constant to any pattern, but usually 

 challenging a comparison with some marbled feather. 



This small but exceedingly pretty species has often interested us 

 in observing its habits. It occupies a hole fitted to the size of its 

 body in our shelving, soft, slaty rocks, where, when covered with 

 water, it expands, in a wide circle, its oral disc and tentacula, 

 raising them scarcely above the level of its habitation. Thus the 

 Actinia retains itself unbosomed, as if proud to display the beauty 

 that its Author has given it ; but should perchance a rude hand or foe 

 touch or ruffle the tentacula, then doth the creature instantly shrink 

 and withdraw within itself and its furrow, until it has become nearly 

 undistinguishable. 



Often a tide will cover the rocks inhabited by a colony of the 

 species with a thin layer of sand. In this case, with the assistance 

 of the tentacula, and by emitting currents of water from the mouth, 

 a small aperture is bored through the sand, through which the ten- 

 tacula 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 and 

 mollusca. 



The deserted holes bored by the Pholas is a favourite retreat for 

 this Actinia ; and hence the specific name suggested by Mr. Price, 

 who finds what I consider to be the same species thus located on the 

 shore at Birkenhead. In confinement, says Mr. Price, the creatures, 

 " even when expanding their little tufty tentacula, keep pretty flat 

 to the glass ; and it is a favour to expand at all." 



In the first edition of this work I have considered this a variety 

 of Act. mesembryantJiemum, with which it has truly no such near re- 

 lationship, for it has no oral tubercles, and it differs not only in 

 colour, but, as Mr. Forbes correctly remarks, " also in habit and 

 shape, being always much more elongated." I had likewise too 

 hastily identified it with Act. viduataoi Miiller, for a comparison of 

 the descriptions will prove that they cannot be made to tally. 



8. A. ALBA, white, longitudinally ribbed, a white line tra- 

 versing each rib from the oral aperture to the base ; tentacula 

 numerous, quadriserial, barred. W. P. Cocks. 



PLATE XXXVII. FIG. 47. 



Hob. Coast of Cornwall, embedded in the crevices of rocks, 

 W. P. Cocl-s. 



