Haddon — On the Fauna of Dublin Bay. 525 



some specimens collected appear to be intermediate between this form 

 and G. hyalina. The latter has only been obtained from Shetland. 

 Lafoea pocillum, Hincks, previously recorded from Oban Bay, and 

 "very rare, on Eudendrium, at Monkstown, D. St. JT. Grant," (B. A. 

 List, p. 4.). I have found it on Biphasia attemiata; it is very rare. 

 L. pygmcea, Alder, is also rare ; previously recorded from Tynemouth 

 and Sark. The rarity of these two species is probably more due to 

 their small size and their being inconspicuous, than to their being 

 absent in other localities. This is also the first recorded Irish loca- 

 lity for Biphasia attenuata, Hincks. 



Especial attention has been paid to the Medusae of the Bay, as 

 they are forms which possess great interest, apart from their beauty of 

 shape and colour. It is very desirable that a Monograph of the British, 

 members of this group should be written, as Forbes' Ray Society Mono- 

 graph, beautiful and invaluable as it is, is necessarily somewhat out of 

 date (1848). With the works of Forbes, AUman, Hincks, Hseckel, 

 and others to refer to, and the modern facilities for research, such an 

 undertaking is easy, compared with the difficulties Forbes had to con- 

 tend against. 



Steenstrupta rubra, Forbes (= S. flaveola, Forbes), was found in 

 June, 1884, in Dalkey Sound; it is the medusa-form of CorymorpJia 

 nutans, Allman {non Qarsfde Hseckel). J. R. Greene, in the British 

 Association Report for 1857 (Dublin), records a Steenstrupia from the 

 Dublin coast, but no details are given ; and Alder found Corymorpha 

 nutans in the Isle of Man. So far as I am aware, this is the whole 

 history of this beautiful and remarkable species in the Irish seas. 

 The Medusa had evidently not long been liberated from the parent 

 stock, as the single tentacle was quite short. I kept it alive for a day 

 or two, and the tentacle grew to about the length depicted in most of 

 the figures. The fixed form must therefore be regarded as an inhabi- 

 tant of Dalkey Sound or its immediate neighbourhood. [S. rubra is 

 very common in Kingstowoi Harbour in June, and, as noted above, the 

 hydroid form is now proved to occur in Scotch Bay.] 



Several species of Sarsia occur : one I identified as S. tubulosa ; 

 another perfectly agrees with Patterson's description of a form met 

 with at Larne, in Forbes' Monograph, p. 56, and which I propose 

 provisionally to name 8. pattersoni, sp. nov. Tiara octona, Forbes 

 (= Oceania turrita, Forbes, and 0. coronata, Allm., according to 

 Hseckel), occurred once. The genus " Thaumantias " is represented 

 by several species, among which I have identified T. hemispherioa, 

 Gron. ; T. inconspicua, Forbes; and T. globosa, Forbes. The latter is, 

 according to Hseckel, Phialidium variabile (= Oceania phospJiorica + 0. 

 flavidula, Per. and Les. 1809 ; = Thaumantias sarnica + T. convexa + T. 

 globosa, Forbes, 1848 ; = Eucope variabilis, Glaus, 1864, &c., &c.). Our 

 knowledge of the forms usually included under the genus Thaumantias 

 is at present in a very unsatisfactory condition, as Hseckel and others 

 have shown ; the genus is undoubtedly polymorphic, and the char- 



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