304 PLUMULARIIDyE. 



subsessile, smooth, divided into seven or eight obscure 

 lobes, borne on the creeping stolon and the main stem. 



THIS species is nearly allied to the preceding, from which, 

 however, it differs in size and general habit, as well as in 

 the minute characters. 



The points in which it differs from P. echinulata are as 

 follows. The plumes are longer, narrower, and less com- 

 pact and graceful. The internodes of the stem are about 

 half as long again as those of P. echinulata, and are of 

 equal width throughout, while those of the latter species 

 taper a little below. The hydrothecae of P. similis are 

 rather large, curving gracefully outwards towards the rim, 

 and free above, with a wide circular opening, and are 

 very unlike the small basin-shaped calycle of its ally ; 

 they are always separated by two joints, while in echinulata 

 there is (normally) only one ; so that the cells are distant 

 in the one species, and comparatively crowded in the other. 



In P. similis there is only a nematophore below the 

 calycles, none above them or in the axils as in P. echinu- 

 lata. And, lastly, the capsules are totally dissimilar. 



Hob. South Devon, abundant on weed in the Lami- 

 iiarian zone; Isle of Man (T. H.): Donaghadee (G. 

 Hyndman): Dublin. 



6. P. OBLIQUA, Saunders. 



LAOMEDEA OBLIQUA, Saunders, in litt. ; Johnst. B. Z. 106, pi. xxviii. fig. 1. 

 CAMPANULARIA, Lister, Phil. Trans. 1834, 372, pi. viii. fig. 5. 

 PLUMULABIA OBLIQUA, HincJcs, Ann. N. H. (3rd. ser) viii. 258. 



Plate LXVII. fig. 1. 



SHOOTS minute, simple and very delicate; STEM flexuous, 

 jointed at regular intervals, pinnate ; pinnae given off at 

 each flexure, alternate, short, bearing a single calycle, and 



