34 Dr. lleid on a new species of Actinia. 



undergo this process, and that not throughout their entire length ; 

 for even a portion of each of those that form young Medusae by 

 transverse divisions of their substance, continues to live as a 

 larva. The first colony I obtained was seventeen months in my 

 possession before any of the individuals composing it underwent 

 its development into young Medusa?. That the larvae, even when 

 living in the ocean, are not always formed in autumn and un- 

 dergo their development into young Medusas in spring, is evi- 

 dent from the fact, that two of the colonies in my possession were 

 obtained from the ocean in July. Whether these larvse had 

 been generated the preceding autumn, and continued to live as 

 such up to the time they were obtained from the ocean, or had 

 been generated at some period subsequent to this, it is impossible 

 to determine. 



Account of a new Actinia. 

 Though the Actinia I am about to describe has in many respects 

 a close resemblance to the Actinia chrysanthellum of Mr. Peach, 

 described and figured in Dr. Johnston's late edition of his work 

 on ' British Zoophytes/ vol. i. p. 220, it yet differs from it suffi- 

 ciently, at least as far as I can make out, to justify me in regard- 

 ing it as a distinct species. If this should be confirmed, I would 

 propose to name it Actinia cylindrica. 



Body elongated, cylindrical, free ; tentacula uniserial, submarginal ; 

 mouth elongated upwards, forming a conical tube with small pro- 

 cesses attached to its margin. 



This animal was found in St. Andrew's Bay, by Mrs.Macdonald 

 and myself about two years ago, immediately after it had been 

 thrown ashore during a storm, and it was kept alive for three days. 

 Fig. 21 (Plate VI.) is a representation of the form of the animal 

 of the natural size. 



The body is cylindrical and marked by longitudinal lines. The 

 inferior fourth of the body is translucent, more contractile than 

 the upper part, and sometimes assumes nearly a conical form with 

 the apex downwards. The upper three-fourths of the body are 

 opake and of a faint pink colour. The tentacula are twelve in 

 number, ranged in a single row, smooth on the surface, of a light 

 pink colour, and having their internal or oral surface crossed by 

 four zigzag white lines (fig. 22). They are elongated trans- 

 versely or flattened from within outwards, and taper towards 

 their free extremity. They were never seen more elongated than 

 what is represented in fig. 21, but as the animal appeared to be 

 languid, it is quite possible they are capable of greater elongation. 

 When contracted to the utmost they formed little conical emi- 

 nences, projecting outwards and upwards, and were seen to be 

 attached immediately below the outer margin of the disc. Twelve 



