S6 EXPEDITION ANTARCTIQUE BELGE 



project but verv slightly. Xo sections hâve been eut of the stouter form with projecting 

 orifices, but it is présumée!, that there is only one species, and that the différence arises from 

 growing on a stouter spine, but this is not an absolute certainty ; in both cases the zoeecia 

 are under i mm long. 



There are about 24-27 tentacles which is a larger number than in most A Icyonidia, though 

 A. albidum Aider, has 25, according to Prouho ; A. variegatum Prouho 28 or more (Prouho) ; 

 A . flustroides Busk 24-27 (Waters) ; A . flabelliforme Kirkpatrick 26-28 (Waters). The number 

 of tentacles in other species is A. gelatinosum L. i5-iy ; A. hirsutum Flem. i5-iy (Hincks) ; 

 A. mamillatum Aider 16-18 (Hincks) ; A. mytili Dalyell i5-i8 (Hincks), 19 (Waters) ; A. para- 

 siticum Flem. i5-i6 (Hincks) ; A. Brucei Calvet 16-18 (C.) ; A. cellarioides Calvet 20 (C). 



The ovaria are at the base of the zoeecia, and consist of a large number of small ovarian 

 cells, of which the largest met with, will be about one quarter the size of those I am figuring 

 in my « Arctic paper» of A. gelatinosum, and also of another Mediterranean species. No 

 doubt the nature, size, shape and position of the ovaria will hâve to be used in the classi- 

 fication of the Alcyonidiidœ. 



The zoeecia are smaller than those of A . flustroides B. and about the size of A. gelatino- 

 sum L. The intertentacular organ is distinctly seen in sections and there are spermatozoa in 

 the same zoœcia as the ovaria. 



A large flabelliform spécimen of Alcyonidiumwa.s brought back bv the Southern Cross 

 Expédition under the command of Borchgrevink, and has been named A. flabelliforme by 

 Kirkpatrick. The A. flustroides B. is from S. Africa and Hincks mentions A. gelatinosum, 

 from Natal, but otherwise the genus is unknown in the southern hémisphère. 



Habitat. — Exp. Antarct. Belge. 



N os 744, io32, Tangles IX. Lat. 70" 20' S.- Long. 83° 23' \\\; 45g met.; +0.8 C. 



Suborder CYCLOSTOMATA 



Cyclostomata from the Antarctic give us much less assistance in the interesting question 

 of distribution, than the more highly differentiated Cheilostomata. Stomatopora, Hornera and 

 Entalophora, or at any rate close allies, hâve lived on since Paleozoic times, being now gene- 

 rally distributed, while the Antarctic species vary but little from those now living in ail parts 

 of the world. Lichenopora is at présent universally distributed, and occurs in the Cretaceous 

 System. 



The most interesting species is Hcteropora claviformis nov. which has been called a new 

 species, although there are some fossils very similar in shape, and there is little else by 

 which to separate it ; however, this is the first time that sections of the soft parts of any of the 

 group hâve been eut, and although the préservation is most unfavorable, Ave find a polypide, 

 similar to that of other C3^clostomata, and the closures are distinctlv shown. Hcteropora is 

 now known récent from Japan, New Zealand, and the North Pacific ; it was abundant in the 

 Tertiaries and Cretaceous, and apparently the family was well represented in Paleozoic times, 

 but it is as yet difficult to bring Paleozoic fossils into line with Cainozoic, and still more so 

 with récent groups. 



