BRYOZOA 77 



To each zoœcium there are several long tubular connections, often about the length 

 of a zoœcium, and they arise from near the distal endofa zoœcium passing to the proximal 

 end of the next younger one, though sometimes one of thèse tubes may skip a zoœcium and 

 join the following one (fig. i3). There are very few connections to the latéral neighbouring 

 zoœcia. In Tubucellaria, Cellaria &c. there is one long Connecting tube, but a number as in 

 T. stellata is unusual. 



There are 18 tentacles, which are narrow, and the tentacular sheath is normal, whereas 

 it is very thick in Orthopora compacta nov. which belongs to an allied genus, both having the 

 ovicells proximal instead of distal. No oral glands were found, though in N° 611 there are 

 buds as well as complète polypides. In spécimen N° 621 the zoœcial cavity is crowded with 

 testes and spermatozoa, and sometimes in the same zoarium there are small ovaria. 



Habitat. — Challenger Station 320 (off Argentine) 600 fath. (970 met.), and Station 142 

 (Cape of Good Hope) i5o fath. (240 met.) ; Cape Horn « Entre les missions et le Détroit de 

 Magellan * (Mus. d'hist. nat. Paris). 



Exp. Antarct. Belge. 



N° 3og (2 spécimens), Tangles II. Lat. 71 14' S.- Long. 8g° 14' \V. ; 460 met.; 4-0. 3 C. 



N os 346 (1 sp.), 1047 (1 sp.), Tangles IV. Lat. 71° 18' S.- Long. 88° 02' W. ; 435 met.; 

 — 0,3 C. 



N os 564 (2 sp.), 922 (2 sp.), 1012, Tangles VIL Lat. 70 23' S.- Long. 82 47' W.; 480 met.; 

 +0.8 C. 



N os 611 (3o sp.), 6i3 (on Orthopora compacta), 619, Tangles YIII. Lat. 70 00' S.- Long. 

 8o° 48' W. ; 5oo ? met. ; +0.9 C. 



N os 621 (2 sp.), 683 (28 sp. some on Cellarinella foveolata), Tangles VIII. d° d°. 



N° 752 (1 sp.), Tangles IX. Lat. 70 20' S.- Long. 83° 23' W. ; 459 met.; 4-0.8 C. 



N os 799 (1 sp.), 800, Tangles X. Lat. 70 i5' S.- Long. 84 06' W. ; 56g met.; +0.8 C. 



RETEPORA 



The Antarctic Rctcporœ seem to belong to two related groups of this genus, and in gênerai 

 character there is much to recall the fossils of the Australian Tertiaries. Three species are 

 related to the R. sinuosa of Kirkpatrick, and it is noticeable that the monilifera group is 

 unrepresented in this collection, apparently having had but a limited distribution, and as a 

 rule the distribution of species of Retepora is but limited. 



As I hâve previously said ('), although there does not seem to be any one character 

 found in ail Reteporœ, yet it seems to be a natural group, as in ail, some or other, of the zoœcial 

 distinctive characters occur, and we may hère mention that there is very generally, and often 

 on both surfaces, a small elliptical avicularium, with a thin mandible, and this form ofavicu- 

 larium might be called a Reteporidan avicularium. 



In nearly ail Rctcporœ there is on the dorsal surface a thick calcareous layer, which when 

 incinerated, readily séparâtes from the front or zoœcial layer (see PL VI, fig. 6a) and on the 



(1) On Mediterranean and New Zealand Retepora &c. [Linn. Soc. Joimi. Zool., vol. XXV, p. 255. 



