138 Proceedings of the Royal Irish Academy. 



The genus Podocoryne has probably generally been confused with 

 the more common Hydractinia, to which there is a strong resemblance 

 in the remarkable polymorphism and habitat. In preserved specimens 

 it is only when one comes to examine closely the chitinous crust and 

 the polypites, that the difference is detected. Both of the two British 

 species seem not uncommon on the west coast. 



In the family of the Bimeridae (Atractilidae) the survey has been 

 very fortunate, five species of these minute forms having been 

 obtained, all of which are new to Ireland. Atractylis arenosa, Alder, 

 is a rare and interesting form. Species of the genus Perigonimus are 

 very common as compared with other localities, and some peculiar 

 forms require yet more comparative examination. Perigonimus (?) 

 linearis, Alder, which is here recorded for the first time for Ireland, 

 has only been once previously obtained from British waters. Dicoryne 

 eonferta, Alder, has also been obtained. The harbour of Glengariff, 

 Co. Cork, has in the past yielded to Prof. Allman the closely allied 

 Eeterocordyle conylearei ; but it is scarcely possible to distinguish 

 between the two from the descriptions given. Very probably more 

 careful examination on the spot will reveal still more of the lesser 

 known gymnoblastic hydroids. 



Amongst the Calyptoblastea, the rare Calycella fastigiata, Alder, 

 is pretty common ; and the peculiar Cuspidella costata, Hincks, has 

 been found on one occasion. This latter is only known from two 

 British localities. 



In the genus Diphasia five species have been dredged, all from one 

 locality, 13 miles south-west of Galley Head. Of these, L.fallax^ 

 Johnston, and B. data, Hincks, are new to Ireland, while B. 

 attenuata has only been once previously recorded. B. fallax is regarded 

 as a northern form, and its present occurrence on the south of Ireland 

 gives it a much greater southern range than was supposed. 



A list of the species obtained from each locality is given at the 

 end of the Paper. 



In the preparation of the Eeport, I have to thank the Eev. Thomas 

 Hincks, P.R.S., our highest authority upon this group, who is ever 

 ready to favour one with his valuable assistance upon the more 

 difficult forms. 



The slides and preparations made will be handed over to the 

 Dublin Science and Art Museum, which has custody of the Academy's 

 material. 



