BRYOZOA 55 



Habitat. - ■ British, Shetland, French seas, Mediterranean, Cumshewa and Houston 

 Stewart Channel (Oueen Charlotte Island), Victoria, Bass's Straits, NewZealand, Singapore (H.), 

 Challenger Station i5i, Heard Island y5 fathoms, Arica (Peru) (d'Orb.), Cape Horn (Muséum, 

 Paris). 



Fossil : Italian Pliocène. The H. desiderata of Novak (') from the Bohemian chalk 

 may be this species. 



Exp. Antarct. Belge. 



N° 570 on stone, 5g 1 on seaweed stalk, 5g6 on shell and stone, 5gj seaweed, Tangles VII. 

 Lat. 70 23' S.- Long. 82" 47' W. ; 480 met. ; +0.8 C. 



X" 820, Tangles X. Lat. 70" i5' S.- Long. 84006' W. ; 56g met. ; +0.8 C. 



SYSTENOPORA 



gen. nov. 



The spécimens described as Systetwpora contracta, do not seem to belong to any established 

 genus, and at présent we cannot tell, which of the characters are of the greatest generic 

 importance, and can only say the characters of the genus are those of the species. The 

 name is taken trom the narrow contracted aperture, which is quite unusual in Cheilostomata. 



There is however a genus Systenostoma of Marsson, and the figure of the cretaceous 

 5. asperulum Marsson ( 2 ) is much like the Antarctic species, which from Marsson's diagnosis 

 might hâve been placée! under Systenostoma ; but from spécimens kindly sent to me by 

 M r Levixsex it is clear that the two things are quite distinct, and the Systenopora of Marssox 

 is probably only Gemellipora. 



On first examination of S. contracta it was thought to belong to the genus Cnciillipora 

 of MacGillivray, however on receiving spécimens of the Australian fossil, for which I am 

 indebted to M 1 " Charles Maplestoxe, it was then seen that they were generically distinct, 

 and Cnciillipora tetrastoma MacG. was found to be closely allied to Lepralia semilaevis Reuss (') 

 from the lower Tertiaries of X. Italv, and it was doubtful whether they should be specili- 

 call}^ separated, but there is perhaps sufficient reason for considering them to be distinct 

 species. Xow, that I hâve the key in the Australian fossil, I find that there was a vibra- 

 culum and not an avicularium in Lepralia semilaevis Réuss. A spécimen I collectée! from the 

 Senonian of Royan, and which I hâve taken to be the Flustrella polymorpha d'Orb. ( + ) has 

 a similarly contracted aperture, with an ear-like projection at one side, and should probably 

 be united with the Antarctic species under Systenopora. The préservation of the spécimen 

 collected at Royan is however not perfect, and Canu ( 5 ) places polymorpha under his subgenus 

 Rynchotella, but I cannot agrée as to there being an)- relationship between Membranipora 

 rhynchota Busk, and what I hâve taken to be polymorpha d'Orb., though possibly d'Orbigny 

 had two species before him when drawing up his description. 



(1) Bry. der Bôhmische Kreideform., p. 86, pi. II, figs. 1, 2. (Daik. K. Ahad. Naturw., XXXVII, Abth. II.) 



(2) Th. Marsson, Die Bryozoen der weissen Scheibkreide der Insel Rùgen. (Palcont. Abhand. Berlin, vol. IV, 

 ), pi, IX, %. 2.) 



(3) Waters, North Italian Brj-ozoa. (Quart. Journ. Gcol. Soc, vol. XLVII, p. 18.) 



(4) Pal. franc., vol. V, p. 286, pi. 697, figs. i3-i5. 



(5) Revision des Bryoz. du Crétacé fig. par d'Orbigny. (Bull. Soc. Géol. de France, vol. XXVIII, p. 368.) 



