306 PLTTMULAUTtD.K. 



Devon coasts ; and I have found it in abundance under the 

 ledges and in the pools near low-water mark on the Cap- 

 stone at Ilfracombe : here it forms miniature groves on 

 the sponge which coats the surface of the rock, or on the 

 roots and stems of weed. It is also extremely common on 

 the coast of Dorset, in Swanage Bay &c. Sidmouth, on 

 Rhytiphlcea (Miss Cutler) : Cornwall (Couch) . 

 [Van Diemen's Land.] 



With compound stem. 



7. P. HALECIOIDES, Alder. 



PJ,UMUI,ARIA HAM:CIOIBE>I, Alder, Ann. N. H. (ser. 3) iii. 353, pi. 12. 



Plate LXVII. fig. 2. 



SHOOTS about an inch high, irregularly branched; STEM 

 compound throughout a great part of its length, simple 

 and very delicate towards the top, very slightly zigzagged ; 

 branches given off from different aspects of the stem, com- 

 pound towards the base, with three joints above the 

 point of origin; pinnce alternate, distant, springing im- 

 mediately below a joint, short, often bearing only a 

 single calycle, and never more than three or four ; HY- 

 DROTHEC.E very distant, separated by two, or rarely three 

 joints; NEMATOPHORES very minute, with a somewhat 

 oblique orifice, one above and one below each calycle, and 

 one on the central stern, above the origin of the pinna ; 

 ooNOTHECjE large, ovate, ribbed transversely, with a broad 

 truncated top, and a very short pedicel, borne on the 

 stem singly or in clusters. 



THE branching of this singularly delicate and beautiful 

 species has a certain constancy in its irregularity. It is 

 almost always one-sided a single branch, of preeminent 

 size, springing from one aspect of the stem (or sometimes 

 two or three) , while the opposite is almost bare. In its 

 mode of growth it is not unlike the genus Halecitim. The 



