50 A MONOGRAPH OF THE 



the surface exhibited stellate pittings very like those on the 

 type specimen of C. Mulleri, but as these are only an acci- 

 dental character, arising from contracting the tissues by 

 drying; there is not much value in their stellate appearance. 

 Tfhe form and proportion of the spicula and gemmules of 

 all parts of the two sponges coincide ; the only diflFerence 

 that I could note was that the hirsute spicula penetrating 

 the crust of the Cape specimen were more numerous in a 

 section examined than they appeared to be in a similar 

 section from Dr. Fleming's British type specimen ; an 

 amount of difiFerence that would probably be found to exist 

 in different parts of the same specimen. I cannot, there- 

 fore, do otherwise than conclude, that they are the same 

 species, notwithstanding the great differences that exist in 

 their localities. 



The history of this sponge presents a singular sequence 

 of errors. In the first place, MuUer is distinctly wrong in 

 the designation of his species, which undoubtedly is Alcy- 

 onium of Ray and Linnaeus, Professor Jameson, perhaps 

 misled .by the stellate mantlings on the surface, believed the 

 sponge from " Fulah and Unst" to be the same as Muller's 

 specimen, and an Alcyonium. Dr. Fleming, at the time of 

 the publication of his ' British Animals,' appears to believe 

 it to be not an Alcyonium, but still identical with Muller's 

 specimen, and accordingly gives it both a new generic and 

 specific name. At last Johnston, seeing that it is not the 

 type of a new genus, sinks both Dr. Fleming's generic 

 and specific names, and correctly assigning the specimen to 

 Geodia, renames it Zetlandica. 



