404 



BRITISH SPECIES OF BEROE. 



The Beroe fulgens, described and figured by Mr 

 Macartney, in the Philosophical Transactions for 

 1810, p. 264. tab. xv. f. 7.-8., probably belongs to 

 the same genus as the one whose characters we have 

 attempted to deliniate. 



" This most elegant creature is of a colour chan- 

 ging between purple, violet, and pale blue ; the body 

 is truncated before, and pointed behind; but the 

 form is difficult to assign, as it is varied by partial 

 contractions, at the animal's pleasure. I have re- 

 presented the two extremes of form that I have 

 seen this creature assume. The first is somewhat 

 that of a cucumber, which, as being the one it takes 

 when at rest, should perhaps be considered as its 

 proper shape. The other resembles a pear, and is 

 the figure it has in the most contracted state. The 

 body is hollow, or forms internally an infundibular 

 cavity, which has a wide opening before ; and ap- 

 pears also to have a small aperture, posteriorly, 

 through which it discharges its excrement. The 

 posterior two- thirds of the body are ornamented with 

 eight longitudinal ciliated ribs, the processes of 

 which are kept in such a rapid rotatory motion, 

 while the animal is swimming, that they appear 

 like the continual passage of a fluid along the ribs. 

 The ciliated ribs have been described by Professor 

 Mitchell, as arteries in a luminous beroe, which I 

 suspect was no other than the species I am now 

 giving an account of 



