606 Scientific Proceedings, Royal Dublin Society. 



Hydranths bottle-shaped, with a double verticil of six to ten 

 large compound capitate tentacles at the base, and three or four 

 simple, sub-sessile ones near the orifice. 



Large thread-cells present in the body of the hydranth, and 

 numerous smaller ones in the tentacles. 



Gonosome (?) 



Habitat. — Growing on Idia pristis, Murray Island, 15 to 20 

 fms. (Station 14), Torres Straits. 



This species closely resembles Cladocoryne pelagica, Allman, 1 

 found growing on the Gulf weed, and might be regarded as merely 

 a variety of the latter. Cladocoryne haddoni is smaller, the greatest 

 height of the stems being 2 mm., whereas C. pelagica attains a 

 height of 5 mm. ; the annulations of the perisarc are more numer- 

 ous in C. pelagica than in C. haddoni ; lastly, the thread cells 

 (fig. 2 b), with regard to their size and shape, are probably 

 characteristic. These organs, before extrusion, appear as large 

 oval cells, measuring -06 x -02 mm. ; when extended, they present a 

 long, slender, filiform portion, followed by a fusiform, barbed 

 termination, which is generally lost. Occasionally the barbed 

 part is in the middle of the thread. The bristles on the barbed 

 end point away from the sac. 



In PL xiv., fig. 2 b (x 375, drawn by camera lucida), the sac 

 is dotted, as it is invisible in the specimen, being buried in the 

 tissue of the polyp. 



The heads of the tentacles bristle with numerous very minute 

 club-shaped threads, with the broad ends terminal. 



A third species of Cladocoryne is C. floccosa, Botch, 2 from 

 Guernsej' ; it is about 12 mm. in height, and the compound 

 tentacles are arranged somewhat irregularly on the body of the 

 polypite. 



Eudendrium infundibuliforme, n. sp. 



(PL xiv., fig. 3). 



Zoophyte pinnate ; main stem dark brown, polysiphonic ; 

 branches simple ; ultimate ramules alternate, contracted and 



1 Allnian, Jour. Linn. Soc. vol. xii. p. 255, PL X. figs. 6, 7. 



2 Rotch, Ann. Mag. Nat. Hist. (Ser. 4), vii. 1871, p. 227. 



