ITS THREAD-CAPSULES. 95 



sently infolds the margin to so great an extent as nearly 

 to conceal the tentacles. The footstalk is also con- 

 tracted by corrugation, but no sooner is it immersed 

 again than this is lengthened, and the tentacles are 

 expanded as before. The changes in the outline of 

 the Ups, and slight jerkings of the body to and fro, 

 or corrugations of the surface in various degrees, 

 constitute the chief of its movements. 



On cutting off the globular head of a tentacle and 

 submitting it to pressure, I found the structure to 

 contain a moderate number of minute thread-capsules, 

 about YY^jth of an inch in length, of two forms : — the 

 one long-oval, apparently carrying a simple thread, 

 the other oval, with a distinct internal chamber near 

 one end, indicating an armature on the thread. The 

 threads were projected from the former in several in- 

 stances, but I saw no example of the propulsion of the 

 latter. 



I afterwards obtained a second specimen of this 

 little Lucernaria, on a similar rocky ledge which runs 

 out from the eastern point of Lulworth Cove. In 

 every respect it agreed with the one above described, 

 which may therefore be considered as representing its 

 normal condition. Though inconspicuous for size or 

 colour, it is a form of much interest to the naturalist, 

 as it is evidently much less aberrant from the Actiniae 

 proper, with which its affinities connect it, than the 

 broad gelatinous-disked species to which the genus 

 Lucernaria was confined before the discovery of L. 

 cyathiformis. Though still peculiar, the form is not 

 very remote from that of the genus Corynactis, by 

 which, as I conceive, it is linked with Actinia. 



