a System of the Calcareous Sponges. 177 



4. 0. guancha,ll. {Guancha.blanca,M.-M.,YaY. A). Lan- 



zarote (M.-M.). 



5. *0. cgathus, H. Gibraltar (H.). 



6. O.pocillivm^H. {Sp.pocillum^Ysih.), Greenland (Fab.), 



Norway. 



7. *0. MsjHdiis, H. Heligoland (H.). 



Genus 3. *Olynthium, nov. gen. 



Ge7i. char. Mouth-opening with a peristomial crown (sur- 

 rounded by a peculiar circlet of freely projecting spicules). 

 Two species. 



8. * 0. mtidwn, H. Algoa Bay. 



9. 0. splendidum, H. Algoa Bay. 



Family III. Sycarida, H. 



Character. The mature calcareous sponge forms a simple 

 sac-like person furnished with a single mouth-opening, and the 

 stomachal wall of which is permeated by regular radial canals 

 (radial tubes). (The radial tubes are lined Avith the vibratile 

 entoderm, open at the distal end outwards through cuta- 

 neous pores, and at the proximal end through stomachal pores 

 into the stomachal cavity, and communicate with each other 

 on all sides by conjunctive pores.) 



Genus 4. *Amphoridium, nov. gen. 



Gen. char. Skeleton consisting merely of simple (linear) 

 spicules. One species. 



\0. A. viride, H. {Ute viridis, O. S.). Cette (O. S.). 



Genus 5. *Amphoriscus, nov. gen. 



Gen. char. Skeleton consisting entirely of quadriradiate 

 spicules. Three species. 



11. A. chrysalis^ H. {Ute chrysalis, O. S.). Lesina (O. S.). 



12. *^. ^irna, H. Caraccas (Gollmer). 



13. ^A. cyathiscus, H. Australia. 



Genus 6. *Sycarium, nov. gen. 



Gen. char. Skeleton consisting of triradiate spicules in the 

 walls of the radial canals, of quadriradiate spicules, the fom-th 

 ray of which projects freely into the stomachal cavity, in the 

 wall of the stomach, and of simple, freely projecting, linear 

 spicules at the distal ends of the radial canals. Mouth-open- 

 ing simple, without thinly membranous rostrum or peristomial 

 crown. Six species. 



