nRYOZOA 



S5 



by vibices and there are numerous elliptical avicularia. The number of tentacles is n and 

 the oral glands are exceptionally long. 



Just under the operculum there is on each 

 side a short tube, arising from the fleshy mass below 

 the operculum, to which the oral glands are attached, 

 and the question now is are thèse the excretory 

 openings of thèse two glands. The ends of the tubes 

 become thicker and were at first taken for the base 

 of spines. Further sections must be prepared and 

 a re-examination of other sections made, but I may 

 add, that though able to find thèse tubes in thin 

 sections they are best seen in thick sections, which 



1 distinguish as « cuts » and such are often the most 

 instructive. 



Thèse tubes were only found quite recentlv, 

 in fact, when I considered the memoir practically 

 finished, but their occurrence is a most important 

 fact which must be further studied and cleared up. 

 In R. hippocrepis I hâve not been able to find any 

 spines, though in allied gênera there are usuallv 



2 or 3, which however are often only found in some 

 parts of the zoarium. In one section there is a tube which unmistakably looks like the joint 

 of a spine and I hâve been led by this to ask if there is any relationship to spines. New 

 in a form of Lepralia Pallasiana, which is the L. Otto-Mulleriana of Moll, there are several 

 spines and from the fleshy mass under the operculum (to which hère also the oral glands are 

 attached) there is a small organic protubérance passing to each spine. This suggests that the 

 oral spines, which hâve received but very little attention, should be carefully examined to see 

 if they are in any way iunctional. 



The R. hippocrepis nov. , R. sinuosa Kirkpatrick, from Victoria, R. gelida nov., and R. 

 lepralioid.es nov. ail seem to hâve an operculum of the Lepralia type, and thèse will form a 

 group of Reteporœ to which perhaps R. Novae Zelandiae Waters should be added. 



Habitat. — Exp. Antarct. Belge. 



X" s 568, 1012, Tangles VIL Lat. 70" 23' S.- Long. 82 47' \\\; 480 met.; +0.8 C. 



X" 991, Tangles VIII. Lat. 70 00' S.- Long. 8o°48' W.; 5oo ? met.; +0.9 C. 



Fig. 3. — Retepora hippocrepis nov. 



A. Section of zoœcium x 85, showing the opercu- 

 lum loi, below which is the fleshy mass, with 

 a tubular process from each side. To this 

 fleshy mass the gigantic oral glands [ogl , are 

 also attached. 



B Section X 25o, showing the tubular process tb 

 below the operculum o . 



C. Section of joint of oral spine. 



CTENOSTOMATA 



Alcyonidium antarcticum sp. nov 



PI. VII, figs. ya-h 



Zoarium growing over the end of the spine of an echinoderm, forming a single layer. 

 The surface is smooth, only indistinct!}- showing the zoœcia, and the thin cortex contains 

 but little extraneous matter. Out of the four spécimens two hâve the zoœcia hexagonal, with 

 the orifices raised and pouting, whereas the other two hâve the zoœcia narrower and the orifices 



