SI'ONUKS. 165 



lotrochota baculifera, RID LI: v. 



1884, lotrochota baculifera, RIDI.KY (16); 1887, lotrochota baculifera, RIDI.KY, var. flabel- 

 lata, DENDY (2). 



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

 small or mere fragments, which I identify with this species. The flal>ellate habit, 

 characterizing my variety flabellata, 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. 104 I find the styli frequently much stouter than the 

 measurements which I gave from Mr. THURSTON'S specimens, often nifasnring altout 

 (V2 millim. by 0'012 millim., but very variable in diameter, while the tylota measure 

 about 0'246 millim. by 0'007 millim., and the birotiilate isocheke about O'Oii millim. 

 long. It will be seen that these measurements agree very closely with those given by 

 RIDLEY for the type specimen from Port Darwin. 



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



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



SUB-FAMILY : PHL(EODIGTYIN^. 



Desmacidon ida3 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, Hwtoderma, 

 Siderodcrma and Amphiaxtrella, which appear to me to form a very natural group. 

 The microscleres are usually more or less completely suppressed. 



Phlceodictyon, CARTER. 



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



LUNDBECK (88) has shown pretty conclusively that CARTER'S name " Phlceodictyon" 

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

 SCHMIDT, being true Chalininse. 



Phlceodictyon fistulosum (BOWERBANK). 



1873, Desmacidon fistulosa, HOWKIUJANK (22) ; 1880, Desmacidon Jeffreysii, CAKTKK (4) : 

 1884, Rhizochalina fistulosa, RIDLEY (16) ; 1888, Rhizochalina fistulosa, RIDLKY and 

 DENDY (1); 1897, Oceanapia fistulosa, TOI-SENT (83); 1904, Phlceodictyon fistulosum, 

 TOPSENT (62). 



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

 Desmacidon Je/reyxii. It differs, however, from the British Oceanapia ./V/fm/xi, as 

 Mr. CAUTER himself pointed ont, in the absence of sigmata. In this respect it agnw 

 with the Australian Phlceodictyon //.s/v'/.wm, \vith which I have no hesitation in 

 identifying it. 



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



