700 Proceedings of the Royal Irish Acade)!)!/. 



disappear or TDecome very scarce. I do not tidnk their disappearance 

 is due to the decrease of temperature, for the usual winter surface 

 tempera tui'e of the sea at Yalencia is ahout 48° P., and the maximum 

 in the summer does not exeeed 61° F. ; so that the difference hetween 

 winter and summer is only about 13° F. Occasionally in Tvinter the 

 sea is belo"w 48° F., but never for any length of time, and the extreme 

 minimum for the thi'ee years (1896-98) was 44°-5 F. Copepods form 

 the principal food supply of the lledusse, and they are faiiiy plentiful 

 throughout the winter, therefore the decrease can hardly be due to 

 starvation. I am inclined to think that it is the rough seas which 

 play havoc with the delicate littoral animals ; and those which escape 

 and turn up early in the spring as matui'e fonns, have passed the 

 winter in deep water far away from the coast. These small Medusae 

 are quite at the mercy of the tides and currents ; they certainly have 

 the power of increasing or decreasing their depth in the water, but 

 not of swimming against the stream, like the large RMzostoma. It 

 seems to be a matter of chance whether they reach deep water or get 

 smashed on the coasts in winter. 



Two papers on British Medusae, written by myself, and published 

 in the " Proceedings of the Zoological Society of London," contain 

 descriptions and figui'es of some of the Medusae taken at Yalencia in 

 1895 and 1896. 



In reports of a faunistic nature I do not think it is necessary to 

 give the full lists of synonyms and references relating to the commoner 

 species, and the few references which are given have been selected for 

 their usefulness. The geographical distribution is only given for the 

 rarer and more interesting species, and when omitted it may be under- 

 stood that the species is widely distributed thi'oughout the British 

 area. 



CRASPEDOTA. 



Order. — AjxinoMEDirsiE. 



Am.ph.inema dinema (Peron et Lesueui'). 



SapTienia dinema, Forbes, 1848, p. 25, pi. ii. 

 Amphinema titania, Haeckel, 1879, p. 50, Taf. iv. 

 Ampliinema dinema, Browne, 1896, P. Z, S,, p. 475. 



In 1896-98 this Medusa made its first appeai'ance in July 

 and disappeared in September, except in 1898, when it re- 

 mained until October. A few specimens taken occasionally 

 during each month. The largest measui-ed 6 mm. ia length. 



