453 



A REVISION OF THE GENERA WITH MICR0SCLERE8 

 TNCLUDEP, OR PROVISIONALLY INCLUDED, IN 

 THE EAISIILY AXIXELLID.E ; WITH DESCRIP- 

 TIONS OF SOME AUSTRALIAN SPECIES. Part i. 



(PoiUFERA.) 



By E. F. Hallmaxx, R.Sc, Linnean Macleay Fellow of 

 THE Society in ZooLora'. 



(Plates xxi.-xxix., figs.Ul'; also xxxix., figs. 6, 7: and Text-figs. 1-9.) 



Genus T H A c H Y c L A D u H Carter. 



Dffi/iiitiou. — Axinellida'(?) typically of arborescent haliit; with 

 an axially condensed, reticulate skeleton of spiculo-spongin fibre. 

 The megascleres are diactinal and of a single category, varying in 

 form horn oxea to strongyla. The characteristic microscleres are 

 spinispirul*, to which are usually added smooth microstrongyla. 



Type-species, 7\ laiviiijnrulifer Carter. 



Inclusive of those here added to it, Trachycladus comprises 

 now se\en species (together with several \arieties), all of ^\hicll 

 are from the southern and south-eastern coasts of Australia. Tlie 

 hitherto-described species referable to the genus are four, nIz., 

 T. la-visjjirulifar Carter (the type-species), and the thi'ee described 

 by Lendenfeld, very im})ei'fectly, under the names Spirophora 

 di<ji(afa, S. hdcterinm^ and Splruphui'e/ladigitata; but, for reasons 

 already indicated in my previous paper, I reject the last-named, 

 relegating it to the synonymy of 7'. diijitahis — a redescription of 

 which is given below. The other two species, T. lo-viiijiiridifer 

 and 7'. Ixictrrivvi, arc apparently unrepresented among those ex- 

 amined by me; Init the latter mav prove to be identical with T. 

 pnsttdosus, sp.n. The specimens from Port Phillip recorded and 

 briefly described as examples of T. hnnspindifer by Dendy(7) 

 appear to me to represent at least two distinct foims, \\ Inch T 

 describe below as varieties of T. rfit,eponi.sn:<, sp.n., and of T. 

 dhjitatiia respectively. 



