(98) 



wliich and the following it seems almost intermediate, but the two 

 membranes of which the frond is composed are but very imperfectly 

 united here and there by scattered slender filaments, and these as the 

 frond advances in age, often become disrupted, and the tube becomes 

 more or less perfect. In the fructification also, there is a very close 

 resemblance, but in the present sj)ecies the club-shaped filaments are 

 more abundant. 



We are informed in Phyc. Brit, that Kiitzing has proposed it as the 

 type of a new genus, and certainly, in these days of hair-splitting, it 

 might be possible to take a less proper course, although the generic 

 characters would certainly not be of the most satisfactory kind. 



EXPLANATION OF PLATE CLX?. 



Fig. 1. — Asjjerococcus compressus, natural size. 

 2.— Surface of frond. 

 3. — Section of same. 

 4. — Same, more magnified. 

 5. — Sorus. 

 6. — Base of frond. All magnified. 



