9 o EXPÉDITION ANTARCTIQUE BELGE 



Habitat. — Exp. Antarct. Belge. 



N° 288, Dredge I. Lat. yi°og' S.- Long. 89 i5' W.; 460 met.; +o.3 C. 



N° 392, Eel trap I. Lat. 71 i5' S.- Long. 87° 3g' W.; 435 met.; — o.3 C. 



N° 5g6, Tangles VII. Lat. 70 23' S.- Long. 82° 47' W.; 480 met.; +0.8 C. 



N° s 623, 683, Tangles VIII. Lat. 70 00' S.- Long. 8o° 48' W.; 5oo ?met.; +0.9 C. 



N° 820, Tangles X. Lat. 70 i5' S.- Long. 84» 06' W.; 56g met.; +0.8 C. 



Diastopora solida sp. nov. 



(PI. IX, fig. 11) 



From N° 373 there are several dead pièces, separated from the base upon which thev 

 grew, and seeing that in ail the pièces the zoœcia are parallel without showing any radiating 

 curvature, it is clear, that the zoarium must grow to a very exceptional size. The zoœcia 

 hâve very thick walls, and the pores passing through the walls are very distinct, as is well seen 

 in spirit spécimens. The ends of the zoœcia are broken away, and were but slightly raised, 

 but near to the aperture the zoœcial tube is about o.i3 mm inside measure, which is larger 

 than obtains in Diastopora generally. The closures are fairly numerous, there being sometimes 

 two in the same zoœcial tube. 



None of the Diastopora obelia group are found in the southern hémisphère. There are, 

 however, several spécimens of Diastopora from Cape Horn, unmentioned by Jullien, but they 

 are more délicate, with the zoœcial tube about half the diameter of those of D. solida and 

 they are either D. concinna MacG. or closely allied. The ovicell is a round inflation with the 

 ovicellular tube turned towards the centre of the zoarium, and the funnel which occurs in 

 D. concinna is not found, nor are any tubule closures, but they may hâve been broken off. 



Habitat. — Exp. Antarct. Belge. 



N° 373, Tangles IV. Lat. 71° 18' S.- Long. 88" 02' W.; 435 met.; — o.3 C. 



Diastopora sp. 



From N° 570 there is a young flabelliform worn colony, in which the tubes do not project, 

 and it might be the D. sitborbicularis Hincks, which occurs in European seas, and also, accor- 

 ding to MacGillivray, in Australia. It is not as stout as D. solida, though in many respects 

 similar, the interior diameter of the zoœcia being about o.8 mm . 



Idmonea atlantica Forbes 



(PL IX, fig. 5) 



There are some pièces of Idmonea without ovicells, which seem to belong to /. atlantica, 

 but where the ovicells are wanting, there is always some uncertainly in the détermination. 

 The séries of zoœcia are about o.8 mm apart, and the external diameter of the zoœcial tube is 

 about o.i4 mm . A spécimen from Cape Horn (Mus. d'hist. nat. Paris) has the zoœcial tubes 

 about the same size, but the séries are o.5 mm -o.6 mm apart. A spécimen from 46, Franz Josef 



