BRYOZOA 



Kirkpatrick, ail from Cape Adare. The species deseribed by Kirkpatrick are ail from the 

 depth of a few fathoms only, and nearly ail were previously known species, whereas the 

 Belgica spécimens are from a moderate depth and a large proportion are new. In considering 

 the meaning of thèse facts we must only draw gênerai conclusions, as the littoral fauna of 

 South America is no doubt better known than the fauna from greater depths. 



It is considered, that there has been a mistake about the spécimens, to which Busk 

 refers, as brought back from the Antarctic bv Sir John Ross, otherwise they would be the 

 first known Antarctic Bryozoa. To thèse spécimens I hâve referred in my paper, on the 

 « Bryozoa from Franz Josef Land », p. 62 &c. and in this memoir when describing H ornera 

 antarctica nov. 



Most gênera of Bryozoa are widely distributed, and there are many cosmopolitan species, 

 so that the Bryozoa fauna from any one locality has some considérable similarity with ail 

 others, but in comparing the Arctic and Antarctic fauna to see to what extent, if any, the 

 bipolar theory receives support, it is not enough to show, that there are some similar foi"ms, 

 for this we should certainly expect, but what we want to know is, whether there is more 

 similarity between the Arctic and Antarctic than between the Arctic and Subantarctic faunas ; 

 then we can carry on oui" comparisons to Southern Temperate, proceeding to Tropical 

 régions and thence on to Northern Temperate. In an}- studies of geographical distribution 

 we must keep in mind the extraordinary mixing of Northern and Australian forms in Japan 

 showing how différent faunas may occur side by side. 



The value of geographical comparisons, however dépends to a large extent upon the 

 certainty there is in the classification ; and with many gênera or groups we are now in a 

 position to use them in studying geographical distribution, whereas in others, and more 

 especially in the Cyclostomata, we had better not attempt much, though there are a few 

 more highly, differentiated species, such as Idmonea radians Lamk. &c. concerning the détermi- 

 nation of which we may feel as sure as with any Cheilostomata. 



However, geographical lists, unless prepared by specialists, are likely to be somewhat 

 misleading, and as an example we may quote a paper valuable for many lists of Subantarctic 

 species of vertebrates and invertebrates, by D r George Pfeffer ('), in which he gives as 

 Antarctic 18 Bryozoa, considered to be identical with those found in the Arctic seas. In the 

 first place he means Subantarctic régions, and only two of those named in his list hâve been 

 found in Antarctic régions. Then he gives Microporella ciliata Pall. and also Lepralia ciliata 

 Pall. but thèse are synonyms, and the same is the case with Schizoporella hyalina L. and 

 Cellepora hyalina L. Eight of the species are Cyclostomata, and there is as yet so much doubt 

 regarding the classification and détermination of this group, that we cannot be sure as to the 

 identity of most of the eight. Further Eucratea chelata L. is cosmopolitan, and the same may 

 be said of Microporella ciliata Pall., Hippothoa (Schizoporella) hyalina L., and Membranipora 

 membranacea L.; Schizoporella spinifera Johnst. is certainly given by Ridley as from Tom Bay, 

 S. W. Chili, but he adds « referred with much doubt to this species », and on reading his 

 description I think we may now décide, that it is not S. spinifera. Fluslra papyracea E. cannot 



(i) Pfeffer, G., Die niedere Thierwelt des antarktischen Ufergebietes. (Internat. Polarforsch. Deutsch. Exp., 

 vol. II, 1890, p. 471.) 



