chap, iv.] THE CRUISES OF THE ' PORCUPINE: 147 



our friend Mr. Gwyn Jeffreys to the somewhat 

 hazardous presumption that "its original home is 

 in the boreal, perhaps even in the arctic region." 



Two very peculiar little sponges were met with here 

 rather frequently sticking to stones. A short smooth 

 column, about 20 mm. in height, is surmounted in 

 one species, which must I think be identified with 

 Thecophora semisuberites, Oscau Schmidt, by a soft 



Pig. -23.— Thecophora semtiuberites, Oscar Schmidt. Twice the natural size. (No 7C. j 



pad of spongy matter, with one or two projecting 

 tubes with oscula in the centre. The other, which I 

 shall call Thecophora ibla (Eig. 24), from its resem- 

 blance to the cirripede of that name, ends in a scaly 

 cone with a single osculum in the middle. The outer 

 wall of the column in both forms is firm and glossy, 

 under the microscope composed of closely-packed 

 sheaves of needle-shaped spicules with their termi- 

 nation blunt and slightly bulbous. The sheaves are 



L 2 



