INTRODUCTION. xi 



are the same as those of the Turkey sponges in 

 the state they come from the sea. 



Gumina exandata, Schmidt, apparently not a sponge. 

 It is a dense cartilaginous substance without spicula, 

 keratose fibre, or any other attribute of the spongiadas. 



Hircinia variabilis, Schmidt, undoubtedly a species 

 of Stematumenia. The skeleton fibres, many of them 

 having the central line of arenaceous and other extra- 

 neous matters, and the membranes abounding with the 

 slender flexuous fibrillsB that characterise the genus 

 Stematumenia. 



Taguilla nigricans, Schmidt. A Hymeniacidon with 

 spinulate spicula. 



Aflysina aerophoha, Nardo. A Verongia, the keratose 

 fibres having large central canals and the sarcodous 

 structures being as dark and dense as those of Dr. 

 Grant's " spongia fistulosa, which I have from the 

 West Indies fresh as it came from the sea. 



Sarcotrag-us splnulosus, Schmidt. A true spongia ; 

 the solid flexible fibres surrounded by an abundance 

 of sarcode. 



Tapiliata suherea ? Schmidt. A Hymeniacidon with 

 spinulate spicula. Very closely allied to Taguilla 

 'nigricans, Schmidt, if not the same species. 



Gaminus vulcani, Schmidt; undoubtedly a pachy- 

 matisma. 



SpongicL nitens, a true spongia with a few extraneous 

 spicula entangled amid its tissues. 



Stegxella saccea, Schmidt. A very delicately con- 

 structed species of Isodictya. Primary lines rarely 

 more than bispiculous. 



Grihrella liamigera, Schmidt. An Isodictya with a 

 coarse open structure ; primary lines multispiculous 

 and numerous minute equi-anchorate sjoicula on the 

 dermal membrane. 



If we refer the specimens of Adriatic sponges I 

 received from Professor Schmidt to the genera 

 founded on anatomical principles adopted in this work, 



