receptacle of that plant for the space of several inches, forming 

 swellings of a dark colour and very slippery surface. 



By Prof. Kiitzing this species alone is retained in the genus 

 fflachistea, the other species of authors being placed by him 

 either in PhycopMla or in Myriactis. There are some minor 

 differences of structure observable among these plants, chiefly 

 as respects the composition and degree of development of the 

 tubercular base, but there is so close a resemblance in habit, and 

 such an identity of nature running through the whole, that I am 

 unwilling to. cumber the science with additional generic names. 



Fig. 1. Shields of Elachistea scutulata on part of a thong of Himanthalia 

 lorea : — the natural size. 2. Vertical slice of a portion of the tubercle, and 

 of the surface of the nurse-plant. 3. Small portion of the same, showing 

 the short filaments (or paranemata) ; a spore ; and one of the long fila- 

 ments, &c. : — highly magnified. 



