L 79 1 



SYNOPSIS OF THE GENERA. 



Sponges are 



Fibro-reticular, the fibres horny 4. Spongia. 

 Spongious with sihceous spicula 



Globose, compact, fleshy 1. Tethea. 

 Polpnorphous, cellular and 

 homologous 



Marine, coloiu-ed 2. Halichondria. 



Lacustrine, green 3. Spongilla. 



Spongious ^\ith calcareous spicula 5. Gk^vntia. 

 Spongious with imbedded inor- 

 ganic gravel 6. Duseideia. 

 Gelatinous without spicula or fibres 7. HxVlisarca. 



" Cum tamen intellectus noster absque divisione et subdivisione entia 

 luimerosissima confundat, confusisque speciebus qutelibet iiotitia vaga 

 et chaotica existat : descriptio rerum methodica maxime iiccessaiia 

 redditur." — O. F. Muller. 



