DuERDEN — On some neio and rare Irisli Polyzoa. 127 



4. Crisia aculeata, Hassall. 



This is regarded by Hassall, Smitt, and Karmer as a distinct 

 species, whilst Busk and Hincks consider it only a variety of Crisia- 

 ehurnea, the principal distinction being that some of the internodes- 

 bear long-jointed spines in addition to the ordinary branches. 

 Harmer, however, shows also that the ovicells of the two are quite 

 distinctive in their characters. The ovicell in the present species is 

 small, prominent near its upper end, and falling away suddenly to 

 the aperture, which is inconspicuous, and never borne on a distinct 

 tube. In C. ehurnea it is large, curved inwards, with a conspicuous 

 aperture borne on a very distinct tube, wider at its base than at its 

 summit. 



Irish Localities. — Kingstown Harbour (Dr. Hassall) : Strangford 

 Lough ("W. Thompson) : Antrim Coast (W. Swanston) : Killiney 

 Strand (J. E. Duerden). 



5. Crisia denticulata, Lamarck. 



This species is easily distinguished from the others by well-defined 

 characters. It has an erect, stilf mode of growth, the internodes con- 

 tain 11-16 zooecia, and the joints in the older parts of the colony are 

 jet black. The branches arise high in the internodes, and " the basis 

 rami are situated very low down on the zooecium, appearing as if 

 wedged in between the zooecium which bears it and the next below 

 it on the same side." 



Under the synonym Crisia luxata, Mem., it is recorded in Thomp- 

 son's JS'atural History of Ireland from Glenarm, Youghal, and the 

 Waterford coast. It is also recorded in the Brit. Assoc. List for 

 Dublin. I have also obtained it on one or two occasions from Dublin 

 Buy, and very abundantly from collections made by Professor Haddon 

 in Dalkey Sound. 



Irish Localities. — Glenarm (Miss Davison, 1833): Youghal (Miss 

 Ball) : Waterford Coast (Miss A. Taylor) : Dublin Bay: Dalkey Sound 

 (Professor Haddon). 



Crisia ramosa, Harmer. 



Crisia ramosa, Harmer, Quart. Jour. Micros. Sc, March, 1891 ; 

 p. 134, pi. xii., figs. 10, 11. 



Mr. Harmer considers the characters of the ovicell so constant in 

 this form that he is forced to the conclusion that it deserves recogni- 

 tion as a distinct species. Although it is evidently alluded to by 



