ZOOPHYTES. 33 



difficult to say what will escape the eye of a pelagic bird, such 

 as gull, guillemot, or hawk-like tern. Their keen eyes 

 distinguish very indistinct objects — for instance, the nucleus 

 of Salpa runcinata, and the minute and almost transparent 

 bodies of the young fishes that flit amongst the splendid masses 

 of swimming jellies (Molluscan and Coelenterate) which some- 

 times throng our western shores. The mere tremor of the. 

 water is almost sufficient to attract such acute and skilful 

 marauders. Moreover the statement of the great naturalist 

 is incomplete without the appendix that many of the Medusas 

 and Hydromedusas are brilliantly coloured and, in addition, 

 phosphorescent, the latter property likewise characterizing the 

 translucent Pyrosoma, and that my distinguished friend Prof. 

 Wyville Thomson regards the luminosity of marine animals as 

 a provision of nature for attracting their enemies in the abysses 

 of the ocean, or for throwing a flood of light on their own prey. 

 I have already* shown my reasons for believing that the theory 

 of the latter author is open to doubt, and shall make a few further 

 remarks on the subject under the Annelida. If the notion had 

 been promulgated that the sexes in the abysses of the ocean used 

 their light to attract each other, and thus had a better chance of 

 continuing the race, perhaps more might have been said in its 

 favour. 



Genus Aurelia, Pe"r. & Les. 



Aurelia aurita, O. Fabr. 

 Abundant in autumn and often so late as November. 

 Genus Cyanea, Pdr. & Les. 

 Cyanea capillata, Eschsch. 

 Common in autumn. 



Order LuCERNARllD.ffi. 

 (Calycosoa, R. Leuck.). 



Genus Lucernaria, O. F. Miiller. 



Lucernaria auricula, O. Fabr. 



[Plate III. figs. 11 & 12.] 



Frequent on Fuci near the commencement of the East 



Rocks, and occasionally at the West Rocks. It is as common 



as in the south. 



* Ann. & Mag. Nat. Hist. 1872, ser. 4, vol. ix. p. 2. 



F 



