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On Tubularia crocea in Plymouth Sound. 



By 



Edward T. Browne, 



University College, London. 



During my visit to the Plymouth Laboratory in September, 1895, 

 Mr. lioach brought in, on the 28th, some fine colonies of Tubularia 

 which he had found attached to the stern of a large three-masted 

 sailing ship, the Ballachulish, of Ardrossau. This ship had come direct 

 from Iquique, Peru, and after staying a few days in the Sound left for 

 London. The Tubularia was kindly given to me for identification 

 by Mr. E. J. Allen. After making drawings and noting the variation 

 of the different organs, I came finally to the conclusion that as it 

 agreed so closely with Parypha crocea, Agassiz, from Boston Harbour, 

 there was no need to add another species to the genus. I was fortunate 

 to meet with colonies of both sexes, and to find the ova in various 

 stages of development. I believe enough material has been preserved 

 to trace the development of the ovum, which shows a remark- 

 able similarity to the development of the ova from the medusa of 

 Hyhocodon 'prolife.r. 



Actinulae were being liberated in large quantities when the colonies 

 were taken from the ship, so it is possible that this hydroid may become 

 an interesting addition to the fauna of Plymouth Sound. 



To distinguish this species it is necessary to examine the female 

 gonophores, and count the number of apical ridges. Agassiz states that 

 the number varies between six and ten, but only eight were present 

 in my specimens. The male gonophore is destitute of ridges, and 

 usually terminates in a blunt apex. In the European species of 

 Tubularia the gonophores are either without ridges, or when they are 

 present their number does not exceed four. 



The stolon ramifies and gives off numerous stems which are branched, 

 twisted, and contorted near the base, so forming a thick, matted mass, 

 from which the simple stems arise to about two inches in height. The 

 stems are not often straight, and are always aunulated at the base, and 



