BY E. A. BRIGGS. 199 



ing to a form of Sertnlarella longitheca."* Additional colonies 

 with gonangia were obtained from Newcastle Bight, N.S.W., and 

 in view of the totally distinct structure and habit of the gonangia 

 they cannot be associated with that species. I now raise Ritchie's 

 variety to sp)ecific rank; the name robusta is preoccupied in the 

 genus, and, therefore, I substitute Sertularella 7'itchiei. 



In the absence of gonangia, Sertularella ritchiei may be distin- 

 guished from. Sertularella longitJieca by its. coarser growth, larger 

 hydrothecse, geniculated stem, and internodes which slope succes- 

 sively in opposite directions. The shapes of the hydrothecae differ 

 in the two species ; in aS'. longitheca a hydrotheca is regularly tubu- 

 lar in shape; in S. ritchiei a hydrotheca is not quite tubular, but 

 reaches a maximum diameter at the point where it becomes free, 

 tapering slightly downwards until it ends in a rounded base, and 

 less markedly towards the mouth. Also, as a general rule, the 

 hydrothecae of S. ritchiei are rather more curved, the lower portion 

 being more erect, and the outward curvature of the upper part 

 more marked than in S. longitheca^ in which, however, the extreme 

 top of the hydrotheca often shows a slight tendency to curve up- 

 ward. The latter species, however, does not show any indications 

 of rugosity on the free adcauline wall of the hydrotheca. The pro- 

 portions of the hydrothecae also differ; in S. ritchiei the hydro- 

 theca is more robust, and is adnate for over a half, and for as much 

 as two-thirds of its length; while in S. longitheca only from one- 

 third to one-half of the hydrotheca is adnate. In S. ritchiei the 

 embayments between the teeth on the margin of a hydrotheca are 

 much shallower, and the teeth, therefore, appear less prominent 

 than do those of S. longitheca. Lastly, the dimensions of S. 

 ritchiei throughout are much larger. 



Locality.— "Thetis'' Station 22, Newcastle Bight, N.S.W., six to 

 five miles from shore ; depth, 40-26 fathoms ; bottom, grey sand to 

 mud and shell; 2nd March, 1898; several colonies with gonangia 

 growing on the horny axis of an Alcyonarian. 



Type Specimen. — In the Australian Museum, Sydney. 



* Ritchie, Mem. Austr. Mus., iv., 16, 1911, p.842, 



