_Spicule_ A minute mineral body of regular and definite shape due not to the forces of crystallization but to the activity of the living cell or cells in which it is formed. _Spongin_ The horny substance found in the skeletal framework and the coverings of gemmules of sponges. Structures formed of this substance are often referred to as _chitinous_. _Subdermal cavity_ A cavity immediately below the derma (_q. v._). _Transverse fibres_ Fibres in the skeleton of a sponge that run across between the radiating fibres. _Tubelliform_ (of spicule) Having a straight shaft with a transverse disk at one end and a comparatively small knob-like projection at the other. SYSTEMATIC LIST OF THE INDIAN SPONGILLIDÆ. [Types, schizotypes, or cotypes have been examined in the case of all species, &c., whose names are marked thus, *.] Genus 1. SPONGILLA, Lamarck (1816). Subgenus A. EUSPONGILLA, Vejdovsky (1883). 1. ? _S. lacustris_, auct. (perhaps in N.W. India). 1_a_. _S. lacustris_ subsp. _reticulata_*, Annandale (1907). 2. _S. proliferens_*, Annandale (1907). 3. _S. alba_*, Carter (1849). 3_a_. _S. alba_ var. _cerebellata_, Bowerbank (1863). 3_b_. _S. alba_ var. _bengalensis_*, Annandale (1906). 4. _S. cinerea_*, Carter (1849). 5. _S. travancorica_*, Annandale (1909). 6. _S. hemephydatia_*, Annandale (1909). 7. _S. crateriformis_* (Potts) (1882). Subgenus B. EUNAPIUS, J. E. Gray (1867). 8_a_. _S. carteri_ var. _mollis_*, nov. 8_b_. _S. carteri_ var. _cava_*, nov. 8_c_. _S. carteri_ var. _lobosa_*, nov. 9_a_. _S. fragilis_ subsp. _calcuttana_*, nov. 9_b_. _S. fragilis_ var. _decipiens_, Weber (probably Malaysian, not Indian). 10. _S. gemina_*, sp. nov. 11. _S. crassissima_*, Annandale (1907). 11_a_. _S. crassissima_ var. _crassior_*, Annandale (1907). Subgenus C. STRATOSPONGILLA, Annandale (1909). 12. _S. indica_*, Annandale (1908). 13. _S. bombayensis_*, Carter (1882). 14. _S. ultima_*, Annandale (1910). Genus 2. PECTISPONGILLA, Annandale (1909). 15. _P. aurea_*, Annandale (1909). 15_a_. _P. aurea_ var. _subspinosa_*, nov. Genus 3. EPHYDATIA, Lamouroux (1816). 16. _E. meyeni_* (Carter) (1849). Genus 4. DOSILIA, J. E. Gray (1867). 17. _D. plumosa_* (Carter) (1849).