9 6 EXPÉDITION ANTARCTIQUE BELGE 



placed under Canccllata, and really made the type, whereas before Lichenopora was the type ; 

 so that both the définition, and the gênera included in the suborder Canccllata hâve been quite 

 changed. When we are able to form satisfactory suborders, it seems most improbable that 

 Lichenopora and Horncra will be in the same. 



Although unable to explain how this confusion has arisen, and which at first I thought 

 was due to a slip in writing, it would seem that Gregory has not understood the structure of 

 what I hâve called the pore tubes, and in speaking of his figure of the section of H ornera (p. 36i), 

 which is not very satisfactory for elucidating the point in question, he refers to fine canals, and 

 says they are the « pores intermédiares » of d'Orbigxy, and the « cavités intersquelettiques » of 

 Pergens, and may be regarded as branched niaculœ. When Gregory first used the name macula 

 (a term, which had already been differently employed in relation to Bryozoa, and must be 

 dropped in this sensé) he clearly meant the pore tubes. He says (Cret. Cat., p. 36oi : «the 

 cancellous character of the walls is due to the présence in them of a séries of maculse » and 

 further on « they correspond in parts with the « pores d'origelles » of [ullien ». 



The pore tubes are closed by a membrane at each end, and the protoplasmic and cellular 

 contents are indirectly in communication with the sea water at the one end, and with the zoœcial 

 chamber at the other, where a disk like rosette plate, with one pore, prevents direct contact, but 

 vital changes are taking place through thèse tubes. 



Similar pores are gênerai throughout the Cvclostomata, and the Cheilostomata ; also 

 shorter pores occur in the interior walls of the Cyclostomata. 



We should indeed be glad to see a man of Gregory' s undoubted abilities dévote him- 

 self entirely to the study of the Bryozoa, but sometimes angel visits stir up ail that has been 

 done without establishing order, and many cases might be mentioned where classification has 

 been left in a much more hopeless condition than it was before; already we hâve a sufficient 

 number of dead classifications, made by those who hâve swooped down on the Bryozoa for a 

 short visit. However talented our friends are, they must not be too hast}', and it can only be 

 by devoting themselves to the work for a long time, that they can give us the real help towards 

 correct classification, which we should like to hâve from them. 



Lichenopora flmbriata (Busk) 



PI. VIII, fig. 20,1 



Discoporetta fimbriaia Busk, Brit. Mus. Cat., pt. III, p. 32, pi. XXVII, figs. 1-4. 



Lichenopora Jimbriai a Busk, Polj-zoa of Kerguelen Islands. {PMI. Trans, vol. 168, p. 194. (7)); Zool. Chall. 



Exp.. vol. XVII. r t. L, p. 26. 

 Disporella spinulosa Jullien, Mission scientifique du Cap Horn, p. 83. 



The one young spécimen from N° 5g6 is no doubt the L. fimbriata of Busk, but I am 

 not at ail sure that it ought to be separated from L. hispida Flem. and at any rate they are 

 closely allied. It belongs to the L. ciliata group. 



Although I hâve examined several spécimens of the L. spinulosa Jullien from Cape Horn, 

 in no case hâve I seen ovicells, and the détermination of Lichenopora when the ovicells are 

 unknown is very difficult and often doubtful. There are in the southern hémisphère several 

 species in which the end of the zoeecium is divided, and in many there are spines on the surface 

 of the zoœcial tube as L. ciliata B. ; L. canaliculata B. = grignonensis B. = venabulum Jullien; 



