74 Mr. G. P. Bidder. 



axis is generally perpendicular to the plane of the spicule .* The 

 pylocyte has as yet only been investigated in homocoel species, 

 it is there amoeboid, and perforates the entire sponge-wall without 

 -any afferent funnel-shaped depression lined by other ectocytes. 

 Branching of the sponge is typically dichotomous or umbellate, with 

 frequent anastomoses, giving rise to reticulate growths supported on 

 solid stalks often of obvious length in the adult. The fourth ray of a 

 .quadriradiate spicule generally (or always) rises perpendicularly 

 from the meeting point of three rays. Lance-headed oxeotes are 

 rarely (or never) present, either in larva or adult. Most species 

 show varieties which are coral-red and sulphur-yellow. 



Order. 1. Ascettida, nov. No quadriradiate spicnles are present. 

 Fam. 1. Clathrinidoe, Minchin (s.s.). There is no distinct pore- 

 loearing dermal membrane. 



Genus 1. Olathrina, Gray. With knobbed ends to the spicnles. 



Sp. : C. clathrus. 

 Genus 2. Guancha, M.M. With pointed ends to the spicules. 



Sp. : G. blanca, coriacea. 



Fam. 2. Leiicascidte, Dendy. A distinct pore-bearing dermal 

 membrane is present. 



Genus 1. Leucascus, Dendy. 



Order 2. Ascaltida, nov. Quadriradiate spicules are present. 

 Fam. 1. Reticulatce, Dendy (s.s.). The radial arrangement of the 

 flagellate tubes is only pronounced near the cloaca. 



Genus 1. AscaUis, H. (s.m.) The flagellate epithelium is not 

 pouched deeply into the wall of the sponge. Sp. : 

 A. cerebrum, A. reticulum, A. primigenia (Leucetta 

 primigenia, H.=zLeucosolenia ventricosa, Dendy ?). 

 Genus 2. Ascandra, H. (sensu Minchin). The flagellate 

 epithelium is pouched deeply into the wall of the 

 sponge. Sp. : A. falcata. 



Fam. 3. Heteropegmidce, nov. The flagellate tubes are completely 

 radial in arrangement. 



Genus 1. Dendya, nov. The ends of the branches, even when 

 united, are distinguishable as separate prominences 

 on the external surface, and there is no true dermal 

 membrane or cortex. Sp. : Dendya tripodifera, 

 ( = Leucosolenia tripodifera (Carter) Deudy (14) ). 



* [In a specimen of G. llanca I find the optic axis at the base of the cup 9 below 

 the external perpendicular on the spicule-plane, while on the solid stalk it rises 

 33 above the perpendicular. This would seem to be consonant with the probable 

 direction in these parts of the line of maximum thrust, and to account for the 

 abnormal "horn" spicules described by Metschnikoff (5) and Polejaeff (7) ] 



