lO'i NATURAL HISTORY OF 



Ampbitroclia rugosa {-^g-), Campauulaire rugueux 

 {De B.). 



Hab. : Common. Usually parasitic on Flustra folia- 

 cea. There is an erect variety which grows to a 

 height of nearly an inch^ but the smaller variety is very 

 common on Flustra. To the naked eye it appears 

 merely as a brown thread, knotted here and there, 

 hardly distinguishable in colour from its host, but on 

 examination with the microscope the knots are resolved 

 into curiously wrinkled cells, *^like little barrels," 

 The gonothec^ are similar in shape to the calycles, but 

 larger, and they have 3 teeth in the opening on the 

 top of each. This species is the " Snail Trefoil Coral- 

 line " of Ellis (" Corallines," 26). He describes the 

 cells as " furrowed like the seed-vessels of the plant 

 called the Snail Trefoil." 



5. S. TENELLA, Aid. 



Sertularia rugosa, var. a. [G. J.), S. tenella {Aid., 

 McA.). 



Hab. : Northumberland {Aid.), South Devon, Filey 

 {Eincks), Peterhead, Wick {C. W.P.), Hebrides, Shet- 

 land {A. M. N.). 



Described by Mr. Alder in the North. Cat. in Trans. 

 Tynes, F. C, iii. 113. The calycles are barrel-shaped, 

 with a 4-toothed aperture. "It is smaller and more 

 delicate than S. rugosa. The polypites appear to be 

 yellow or orange colour." 



6. S. FusiFORMis, HincJcs. 



Hab. : South Devon, Ilfracombe {Hindis), Torbay 

 (Parjitt), Hebrides {Norman). Height j — 1 in. Stem 

 slender, ringed at base and below each calycle. Caly- 

 cles flask-shaped, smooth, aperture 4-toothed, one to 

 each interuode. 



