682 Proceedings of the Royal Irish Academy. 



1898. It occurred from March to November. During May- 

 young stages, 2-3 mm., were common. Early in July 

 specimens, 3-5 mm., and at the end of the month, 

 6-12 mm., were abundant. During August and Sep- 

 tember both early stages, 2-4 mm., and large adults, 

 15-25 mm., were abundant. 



I am inclined to believe that there are two generations in a 

 year. The larval forms, so numerous in the autumn, which sur- 

 vive the winter storms by remaining near the bottom in fairly deep 

 water, reach the adult condition early in the following year, and 

 produce the spring generation which is found during April and 

 May. This generation growing rapidly during the warm summer 

 months produces the autumn generation, which is more numer- 

 ous, having been reared under more favouiable circumstances. 



M'Intosh (1889) gives an excellent account of the distribu- 

 tion of this species at St. Andrews for the year 1888. 



Bolina norvegica (Sars). Sp. ? 



The identification of this common but beautiful lobate Cteno- 

 phore has yet to be verified. When I was at Vsilencia I had 

 no means of identifying the species, owing to the absence of 

 the necessary books, and the numerous attempts to preserve 

 specimens by different methods all terminated in absolute 

 failure. The early larval stages killed in Flemming's solution 

 and transferred to alcohol were passable, but the large speci- 

 mens contracted almost beyond recognition. 



1895. Only three specimens taken in April, and a few occa- 



sionally diuing May. Most were young stages. The 

 largest specimen measured 32 mm. in length, 



1896. From July to the end of September there was a mixtui*e 



of early stages and large adults. During July young 

 forms, 1-10 mm. in length were common, but adults 

 over two inches were scarce. August was the prin- 

 cipal month for large specimens. They were abun- 

 dant on August 1st, 4th, 10th, and 24th; and very 

 abundant (in shoals) on August 12th, 15th, and 22nd. 

 The adult specimens ranged from 60 to 80 mm. in 

 length, and 30 to 40 mm. in width. There was a 

 considerable decrease in numbers after the first week 

 of September. The last specimen was seen on Sep- 

 tember 24th, two days after a heavy gale. 



