366 Prof. Hickson, On Alcyonaria i7i the Cambridge Museum 



On some Alcyonaria in the Cambridge Museum. By Sydney J. 

 Hickson, M.A., F.R.S., Professor of Zoology in the University of 

 Manchester. 



[Read 7 March 1921.] 



Clavidaria dura n.sp. 



A very small specimen of a creeping Clavularia was found in 

 the collection made by Dr J. C. Verco in 20-30 fathoms off Adelaide, 

 S. Austraha. The stolon consists of a few flat strands about 5 mm! 

 in width attached to the horny tubes of a Gymnoblastic hydrozoon." 

 On this stolon there stand at considerable distances apart five 

 calices in the shape of inverted cones 1-5 mm. in height with a 

 diameter of -8 mm. at the distal end and 0-3 mm. at the end where 

 it is attached to the stolon. At the free base of each cone {i.e. 

 the distal end of the calyx) there are eight grooves radiating from 

 the centre but the circumference of the cone is quite smooth. 



The body wall of the stolon and of the cahces is rendered 

 perfectly rigid by a dense amalgamation of calcareous spicules, as 

 m Tubipora, Telesto rubra and Sarcodictyon. So hard are the calices 

 that I was unable to break them open with a pair of needles and 

 it required a sharp blow on the cover-glass to crush them. When 

 a calyx had been thus crushed the tentacles were seen to be armed 

 with numerous spicules in the form of curved rods 0-1 mm. in- 

 length with a few small tubercles. The whole colony was pure! 

 white in colour. In form and habit this new species approaches 

 very closely the Clavidaria ramosa from the coast of Victoria* but 

 differs from it in the hardness of the walls and the restriction of 

 the eight grooves to the distal end of the calyx. Moreover in the 

 new species I have not been able to find any of the double club 

 spicules which are so characteristic of C. ramosa. 



Sarcodictyon catenata Forbes. 



An Alcyonarian having very much the same appearance as the 



British Sarcodictyon catenata of Forbes was sent to the Museum 



by Dr J. C. Verco from 20-35 fathoms off Adelaide, S. Austraha 



in 1904. ' 



The interest of this specimen hes in the fact that the genus 

 Sarcodictyon has been found hitherto onlv within the British 

 sea area. 



In a former paperf I expressed agreement with Sars in sug- 

 gesting that the genus should be merged ^\'ith Clavularia and I ' 



* Hickson, Trans. Zool. Soc. Lond. xm, 1894, p. 340 

 t Op. cit. p. 332. ^ 



