a System of the Calcareous Sponges. 181 



Genus 15. Sycinula, 0. Schmidt. 



Gen. char. Skeleton as in Dyssycum. Mouth-opening sur- 

 rounded by a peristomial crown (a simple circlet of freely 

 projecting spicules). Three species. 



60. 8. aspera^ O. S. Corfu; Dalmatia (O. S.). 



61. 8. Eg edit, O. S. Greenland. 



62. ^8. echinata, H. Algoa Bay. 



Order II. POLYSYCA, H. 



Character. The mature calcareous sjyonge forms a stock 

 with several mouth-openings. (Body more or less branched, 

 with the branches free or repeatedly united and anastomosed, 

 forming sometimes little shrubs or bushes, sometimes a densely 

 interlaced root-work or a spongy mass. Stomachal cavities of 

 the persons composing the stock communicating with each 

 other directly or indirectly, with a separate mouth-opening at 

 the free end of all or of several branches (persons).) 



Family V. Soleniscida, H. 



Character. The mature calcareous sponge forms a stock 

 with developed persons, each of which possesses a mouth- 

 opening, and the stomachal walls of which are traversed by 

 simple cutaneous pores, as in the Olynthida. 



Genus 16. Leucosolenia, Bowerbank. 



Gen. char. Stomachal cavities and their communicating 

 tubes simple, not chambered. Mouth-ojsenings of the per- 

 sons simple, without either proboscis or peristomial crown. 

 Twenty-one species. 



Subgenus 1. Leucalia. Spicules all simple (linear). (The outer 

 parts of the spicules project beyond the outer surface.) 



63. *7y. coralloidesj H., and 



64. *Zy. troglodytes^ H. Naples (H.). 



Subgenus 2. Leucelia. Spicules all triradiate. (Inner and 

 outer surfaces of the tubes smooth.) 



65. *Z. dictyoides^ H. Australia. 



Q)Q. L. himantia, H. {Grantia hotryoides^ var. himantia,J.). 

 British coasts (J.). 



67. L. coniplicata, H. (Sj). coniplicata, Montagu). British 



coasts (Mont.). 



68. L. guancha, H. [Guancha blanca, var. B, M.-M.) 



Lanzarote (M.-M.). 



69. L.jpnlchra^O.^. Dalmatia (O. S.). 



