3 4 EXPEDITION ANTARCTIQUE BELGE 



Chaperia cylindracea Busk, var. protecta nov. 



IP1. II. fig. 3) 



Type Ehctra cylindracea Busk, Zool. Chall. Exp., vol. X, pt. XXX, p. 78. pi. XXXIII, fig. 2; Waters, 

 Suppl. Report. Zool. Chall. Exp., vol. XXXI. pt. LXXIX, p. 12, pi. I, figs. i3. 14: pi. III, fig. 23. 



This agrées in the main characters with the Challenger spécimens, but it differs in 

 the shape of what Busk called the « hollow process », which might in the variety be called 

 a protecting plate with irregular cervicorne growth on each side, and bearing on the front in 

 the centre an elongate avicularium directed downwards. The spécimen is only small, and 

 encrusts the stalk of a seaweed. 



The avicularium above the oral aperture is similar in this and in the Challenger type, 

 and on each side of it there is a spine which becomes wider at the extremity ; still lower down 

 by the border, there is another spine, more or less flattened and curved. The ovicell bears 

 one or two « hollow processes », similar tu those in front of the opesia, but smaller. 



Protecting plates or processes are also known in « Membranipora imbricata » Busk, and in 

 icAmphiblestrum umbonatum » Busk, and further the so-called « opercular spine » of Membranipora 

 bellula Hincks, is similarly placed. The structure of the « hollow process » was not quite 

 correctly appreciated by Busk, and therefore I attempted to make it clearer by figures i3, 14 

 in my Supplementary Report. 



Habitat ; type. — Prince Edward Islands 8o-i5o fathoms (170-240 mètres). 



Exp. Antarct. Belge. 



N° 5gi, Tangles VII. Lat. 70° 23' S.- Long. 82" 47' W. ; 480 met. ; -fo.8 C. 



CELLARIA. i 1 ) Lamouroux 



Cellaria is a genus now generally distributed, and has been common through the 

 Tertiaires, while the family Ccllaridœ is represented in the Cretaceous, though the cretaceous 

 forms are not articulated, at an} 7 rate not in most cases. It is, however, doubtful whether 

 some as for instance Escharinella elegans d'Orb. should not be placed in the genus Cellaria. 



A point of considérable importance is, that we can in the genus find various characters 

 showing resemblance to Cretaceous fossils allied to the living Onychocella, and which we may 

 for convenience speak of as the Onychocellidœ. 



In the Escharella Argus d'Orb. ( 2 ) (also called Escharifora) of which I hâve given a fresh 

 figure in my paper on the Melicerititidœ ( 3 ), we find a pair of superior and inferior teeth just 



(1) It has recently been suggested that we should call this genus Cellularia Pallas, but as I hâve said 

 (Notes on Bryozoa from Rapallo, Linn. Soc. Journ. Zool., vol. XXVI, p. 3) the rétention of the name Cellularia 

 has long been most undesirable, as it has been used in such various sensés. Pallas who gave the name included 

 under it Tubucellaria, Cellaria, Notamia, Bugula, Scrupoccllaria, Eiicratea, Aetea, and other gênera. As Tubuccllaria 

 opuntioides was the first mentioned, this would be the type ; and the only genus to which according to the laws 

 of prioritv the name could be applied is Tubuccllaria. This shows how impracticable it is to revert to old gênera 

 based on characters now known to be valueless. 



(2) Pal. fr., vol. V, p. 209, pi. 666, figs. i3-i6. 



(3) Ann. Mag. Nat. Hist., ser. 6, vol. VIII, pi. VI, fig. 7. 



