37 
A NEW IRISH POIvYZOON. 
HyPOPHORKIwLA expansa, EhIvKRS. 
BY A. R. NICHOI.S, M.A., M.R I.A: 
This interesting Polyzoon, which inhabits passages that it 
forms in the substance of the tubes of certain marine worms 
(Chaetopterus and Lanice), has been found at a few places off 
the Continent of Europe, but has hitherto only been recorded 
from British coasts by Harmer, who found it in Cliaetopterus 
tubes dredged in 30 fathoms off Plymouth.'' 
I have been working recently on the Polyzoa of the Irish 
coasts and have examined some tubes of Chaetopterus dredged 
by the late A. G. More in Broadhaven, on the coast of 
Maj^o, in July, 1873". stripping off thin layers from the 
inner surface of these peculiar parchment-like tubes and 
examining them with the microscope,. I soon discovered the 
presence of Hypopho7xlla expansa by the delicate thread-like 
connexions (stolons) between the zooecia ; a few zocecia in a 
rather damaged condition and some of the small holes through 
which the tentacles are protruded into the interior of the worm 
tube could also be seen. The appearance, under the micro- 
scope, of those portions of the la3^er which contained colonies 
of H3^i)ophorella, resembled closely the figures given by 
Joyeux-Iyaffuie.^ 
This Polyzoon was found by Ehlers in the substance of the 
tubes of Tei'ebella {Lanice) conchilega and named Hypophorella 
expa7isa \ subsequently it was found in the tubes of Chaetopterus 
by Joyeux-Iyafifuie, who, not recognizing it as the same species 
that Ehlers had previously discovered, renamed it Delagia 
chcEtopteri. Hypophorella was also found in tubes of Chaetop- 
terus by Prouho and Harmer, and, as the latter remarks, is 
probably common wherever this worm occurs. Specimens of 
Chaetopterus have been recorded from various places on the 
west coast of Ireland, but I have only had an opportunity 
of examining those from Broadhaven. 
1 Note on New or Rare British Marine Polyzoa. foiirn. Mar. Biol. 
Assoc., 1897, pp. 51-53. 
* Ivife and I^etters of Alexander Goodman More. DubUn, 1898. 
» Description du Delagia chaetopteri (J. J.-L.) Archives de Zool. Exp. 
et Gin. (2), vi., 1888. 
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