REPOET ON THE MONAXONIDA. 



xlv 



very much smaller lacunar channels take their origin, and from these again smaller ones ; 

 and here again the lacunae are surrounded by the flagellated chambers (PI. LI. fig. la). 



In Stylocordyla stipitata, var. glohosa, the inhalent canals are also, at any rate near 

 the surface of the sponge, represented by a system of lacunar channels surrounded by the 

 flagellated chambers (PL L. fig. 1). 



We have in no case found the inhalent canals breaking up into a system of finer and 

 finer canals, of which the ultimate ramifications end each in a single flagellated chamber. 

 This, however, is probably due to the insuSiciency of the time and material at our 

 disposal, for such a condition is described by Vosmaer in Trichostemma {Polymastia) 

 hemisphxricum,^ and, judging from other accounts, of which, however, none are very 

 definite, would appear to occur also in some other Suberitidse. That it does not occur in 

 all the Clavulina we have already shown ; for in Latrunculiawe have found the lacunar 

 condition as above described, and Pol^jaefl" informs us^ that Suberites domwncula also is 

 "characterised by an entire absence of special cameral canaliculi." 



(4) The Flagellated Chambers. 



The flagellated chambers appear, from our researches, to be nearly always globular or 

 subglobular in form in the Halichondrina, and either globular or oval in the Clavulina. 

 In size they vary from about 0-024 to about 0-058 mm. in average diameter. 



The following table of measurements and forms as observed by us in eighteen speciesmay 

 be of use in showing the relative sizes and shapes of the chambers in the difierent groups : — 



1 Sponges of the " Willem Barents" Expedition, 1880-81, p. 13. 



2 Zool. Chall. Exp., part sxsi., Report on the Keratosa, p. 80. 



3 It is of especial interest to have succeeded in finding the flagellated chambers in this sponge, as both Vosmaer and 



