(152) 



This species may generally be known from the last by its more 

 slender and straggling habit, and somewhat less regular branching ; 

 the branches are very patent or even recurved, the ultimate ones 

 scarcely erect, yet it certainly approaches very near the last species, and 

 may be only a deep water variety of that variable plant, which puts on 

 various habits according to situation, season, and other circumstances. 

 Our specimens were dredged in Belfast Lough, and were kindly commu- 

 nicated by Dr. Dickie ; they are without fruit, which we have not seen. 



It is said to be always found in deep water, and generally grows 

 entangled among other small Algge, which may in some measure account 

 for the difference in habit. 



SPHACELARIA SKRTULAKIA. 



EXPLANATION OF DISSECTIONS, &c. 



Fig. 1. — Sphacelaria sertularia, natural size. 

 2. — Pinna. 

 3. — Apex of pinna. 

 4. — Joints of tlie stem. All magnified. 



