706 Proceedings of the Royal Irish Academy. 



Euphysa aurata, Forbes. 



Eupliysa aurata, Forbes, 1848, p. Vl, pi. xiii. ; Haeckel, 1879; 

 Browne, 1896, P. Z. S., p. 474. 



In 1895, dui'ing my visit in tbe spring, this Medusa was 

 usually present in tbe tow-net. Tbe smallest specimen 

 measured f mm. in length., and tlie largest about 3 mm. 



In 1896, only two specimens were taken in August; one was 

 quite an early stage, about 1 mm. in lengtb, and tbe otter an 

 adult witb. ova. Tbe Misses Delap sent me two immature 

 specimens taken early in ISTovember. 



In 1897-98, it appeared in April and disappeared in June. A 

 solitary specimen was taken in September, 1897. 



This Medusa never became abundant ; usually only a few 

 were specimens taken at one time. 



It reaches matuiity in May. The life-history of the species 

 is still unknown. 



Euphysa aurata may be distinguished from Corymorpha nutans 

 by not possessing a pointed, cone-shaped process on the top of 

 the umbrella ; and from Syhocodon prolifer by not having the 

 tentacular side of the umbrella longer than the opposite side, 

 and by not possessing Medusa -buds. 



Hybocodon prolifer, L. Agassiz. 



Sylocodon prolifer, Agassiz, 1862; Allman, 1872; Browne, 1896, 



P.Z. S., p. 466. 

 Amphicodon ampliipleurus, Haeckel, 1879, p. 37, Taf. i. 

 AmpMcodon fritillaria et glolosus, Haeckel, 1879. 



In 1895, I arrived at Valencia about the time the Medusa 

 was disappearing, and only a few specimens were taken during 

 the fii-st fortnight in April. All the specimens had reached 

 maturity ; some with ova upon the wall of the stomach, others 

 with free Actinulse inside the umbrella-cavity. 



In 1897, a solitary specimen was taken on February 15th, 

 with eight Medusa-buds upon the base of the large tentacle. 

 Another specimen was taken on June 1st. 



In 1898, none were seen. 



The Medusa is liberated from the Hydroid Hylocodon prolifer, 

 which has not yet been recorded in British seas. The Medusa, 

 at fii'st, has only one solitary tentacle, but later on develops 

 two more, one on each side of the fii'st tentacle. 



