495 



A REVISION OF THE GENERA WITH MICROSCLERES 

 INCLUDED, OR PROVISIONALLY INCLUDED, IN 

 THE FAMILY AXIKELLID.E ; WITH DESCRIP- 

 TIONS OF SOME AUSTRALIAN SPECIES. Part ii. 



[Porifp:ra.] 



By E. F. Kallmann, B.Sc, Linnean Macleay Fellow of 

 THE Society in Zoology. 



(Plates xxix., fig.4; xxx.-xxxii ; xxxiii., figs. 1-5; xxxiv.-xxxvii.: 

 xxxviii., tigs. 1-3: and Text-figs. 10-1 6.) 



Genus B I E M N A Gray (sens. lat.). 



Definition. — Axinellida? typically of massive or encrusting 

 habit, occasionally tending to become lamellar or calicular, 

 almost invariably provided with conuli or other surface-eleva- 

 tions of less regular form, or with digitate processes either solid 

 or tubular; or, finally, consisting almost entirely of tubular pro- 

 cesses. The skeleton varvina;, sometimes conformintr more or 

 less to a halichondroid type, but more frequently consisting 

 of definite fibres, which sometimes are arranged reticulately. 

 The spicules composing the fibres are sometimes (in the less 

 typical species) arranged more or less plumosely, or even in part 

 echinatingly. The megascleres are typically of a single order, — 

 either styli alone, or styli together with oxea of similar dimen- 

 sions; special dermal megascleres are absent. The microscleres 

 are invariably sigmata and trichites (or microxea), the latter 

 usually or perhaps always occurring (partly at least) in dragmata; 

 and to these may be added commata, microstrongyla, or spherulae. 



Type-species, B. peachi Bowerbank. 



The species for which the genus Allantophora was proposed by 

 Whitelegge(58) differs in the combination of its characters so 

 notably from any species known previously to it, and, in one 

 important respect at least, so considerably also from any which 



