726 Proceedings of the Royal Irish Academy. 



found it necessaiy to give a new specific name to this species, 

 so as to make sui'e of its identity and to save further trouble, 

 as the literature connected with the two genera Tliaumantias 

 and PMalidium is in a hopeless state of confusion, mainly 

 brought about by the early observers not recording the 

 marginal sense organs. The same set of Medusae are described 

 in two distinct families by Haeckel — Thaumantidae (sense 

 organs without otoliths) and Eucopidse (sense organs with 

 otoliths). The early and the intennediate stages have also 

 been classified into distinct genera and species, which are 

 divided between the two families. 



Polycanna forskalea (Forbes). 



^quorea forskalea, Porbes, 1851, P.Z. S., p. 272, pi. iv. 



Polycanna forskalea, Browne, 1897, P.Z. S., p. 828. 



Li 1896, a single specimen was found on September 4th, and 

 on the following day five specimens were taken in a hand-net, 

 and others seen swimming too deep down to be captured. On 

 September 7th another specimen was taken. These specimens 

 have been fully described in the P. Z. S., 1897. 



In 1897, eighteen specimens were taken by the Misses Delap 

 on July 26th ; the largest about 40 mm. in diameter. Two 

 specimens were taken on July 30th and one on August 7th. 



In 1898, specimens were taken on the following dates : — 

 July 25th. Two specimens ; largest about 65 mm. 

 July 30th, Three specimens. 



August 23rd. Two specimens; largest about 130 mm. 

 October 11th. Two damaged specimens. 

 IS'ovember 5th. One large specimen of a bright pink colour. 



The specimens taken in 1896 agxeed with, the description 

 given byPorbesfor a Medusa which he caVie^ ^quorea forskalea 

 (Peron), and found by him in the Outer Hebrides. I think that 

 the descriptions given by the writers previous to Porbes are 

 rather incomplete, and for the present I prefer to call this 

 species P. forskalea (Porbes), and to leave the question of 

 priority for further investigation. 



Greene (1858) has recorded an .^2'«<o?rff (sp.?) for Dublin Bay, 

 and for several places on the south-west coast of Ireland where 

 it occurred in considerable numbers. Prom the description 

 given it appears to be a young stage (umbrella not exceeding 

 an inch in diameter) of an ^quorea or a Polycanna. 



