472 EICHARD EVANS. 



Minchin, Fellow of Merton College, Oxford, who in turn 

 handed it over to me that I might study it. There were, 

 besides four specimens preserved in alcohol and kept in 

 separate bottles, a number of fragments which had been most 

 carefully preserved, some in corrosive sublimate, and the rest 

 in Flemming's fluid, and which were kept apart in separate 

 tubes. 



On examination all the material, with the exception of one 

 small piece of that which had been preserved in corrosive sub- 

 limate, proved to belong to the same species. The small piece 

 mentioned above must have been cut from a sponge which in 

 its external appearance was almost exactly similar to the one 

 to which the bulk of the material belonged, however different 

 it may be in its skeletal characters, or else Mr. Moore would 

 have noticed the difference. However great the external 

 similarity, a single glance at a section suffices to distinguish 

 them as belonging to two entirely different species. 



I have given these species the names Spongilla moorei and 

 Spongilla tanganyikse respectively. The former species 

 is represented by the bulk of the material, and is named in 

 honour of its discoverer. 



Of the latter I had but a small fragment, and have chosen 

 its designation from its locality. 



II. Description of Spongilla moorei. 



(1) Habits of Growth and External Form. — Spon- 

 gilla moorei grows on shells of various mollusca, and par- 

 tially covers them as a crust. The upper surface is raised into 

 lobes or mound-like elevations, which in no case are more than 

 half an inch above the general surface, and which are usually 

 no more than an eighth of an inch above the shallow depres- 

 sions which separate them. The surface texture of the pre- 

 served sponge is somewhat woolly in appearance, though this 

 is probably the result of the broken condition of the dermal 

 membrane, for it has been observed that some of the fragments 

 preserved in Flemming's fluid are smooth, and the spicules of 



