CHAP. 1V.] THE CRUISES OF THE ‘ PORCUPINE, 147 
/ 
our friend Mr. Gwyn Jeffrevs 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 senisuberites, OSCAR Scumipt, by a soft 
Fic. 23.—Thecophora semisuberites, OScAR Scumipt. Twice the natural size. (No. 76.) 
pad of spongy matter, with one or two projecting 
tubes with oscula in the centre. The other, which I 
shall call ZLhecophora ibla (Fig. 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 
