SPONGES. 165 



Iotrochota baculifera, Ridley. 



L884, Iotrochota baculifera, Ridley (16) ; 1887, Iotrochota baculifera, Ridley, var. flabel- 

 lata, Dexdy (2). 



There are in the collection a number of dark purple-coloured specimens, mostly 

 small or mere fragments, which I identify with this species. The flahellate habit, 

 characterizing my variety Jlabellata, is not recognisable in most of them, and it seems 

 hardly worth while to retain a special varietal name for the Ceylon form. In a 

 boiled-out preparation of R.N. 1G4 I find the styli frequently much stouter than the 

 measurements which I gave from Mr. Thurston's specimens, often measuring about 

 - 2 millim. by 0*0 12 millim., but very variable in diameter, while the tylota measure 

 about 0'246 millim. by 0'007 millim., and the birotulate isocheke about 0"02 millim. 

 long. It will be seen that these measurements agree very closely with those given 1 > v 

 Ridley for the type specimen from Port Darwin. 



Thiele (39) has recorded the species also from Celebes. 



R.N. 47 (Gulf of Manaar) ; 164; 317 ; 322 ; 331 (all from Ceylon seas). 



Sub-family : PHLCEODICTYDSME. 



Desniacidonidae in which the sponge body is provided with fistular outgrowths, and. 

 usually at any rate, with a spicular rind or cortex. 



In this sub-family I include the genera Phlceodictyon, Oceanapia, Histoderma, 

 Sideroderma and AmpMastrella, which appear to me to form a very natural group. 



The microscleres are usually more or less completely suppressed. 



Phlceodictyon, Carter. 



Phloeodictyinse with oxeote or strongylote megascleres and no microscleres at all. 



Lundbeck (88) has shown pretty conclusively that Carters name "Phlceodictyon" 

 must be revived for this genus, the type species of " Rhizochalina" described by 

 Schmidt, being true Chalininse. 



Phlceodictyon fistulosum (Bowereank). 



1S73, Desmacidon fistulosa, Bowerbank (22) : 1880, Desmacidon Jeffreysii, Carter (4) : 

 1884, Rhizochalina fistulosa, Ridley (16) ; 1888, Rhizochalina fistulosa, Ridley and 

 Dexdy (1); 1897, Oceanapia fistulosa, Topsent (83); 1904, Phlceodictyon fistulosum, 



TOPSENT (62). 



Mr. Carter recorded this species from the Gulf of Manaar under the name 

 Desmacidon Jeffreysii. It differs, however, from the British Oceanapia jeffreysi, as 

 Mr. Carter himself pointed out, in the absence of sigmata. In this respect it agrees 

 with the Australian Phlceodictyon fistulosum, with which I have no hesitation in 

 identifying it. 



In a footnote to the account of this species in the Report on the "Challenger" 



