PEEFACE. 



The following pages contain an amended list of 

 the British. Spongiad^, with notes on some of the 

 species previously described, and descriptions of many 

 new forms. 



The arrangement and nomenclature of Dr. Bow- 

 erbank has been of course strictly adhered to 

 throughout. 



The descriptions of new species, and all such other 

 passages as will be found within inverted com/mas, are 

 the work of the author, and were either already 

 actually in type, or were found among his manuscripts 

 at the time of his decease. 



For the rest the editor is responsible. 



His aim has been, first, to give a complete list of 

 the species described in the four volumes, with com- 

 plete references to all that is to be found respecting 

 them, that it may form a key to the whole. Secondly, 

 to supply recent synonyms ; but hardly any references 

 to works published antecedently to the first volume of 

 this work have been recorded. Thirdly, to give 

 additional habitats. FoWthly, to add notes on certain 



