{ 5'2 ) . 



into broad obcuneate segments, one to three inches broad, often again 

 once or twice divided ; the segments broad iipwards, the apices rounded 

 and more or less deeply divided into linear lacinise, obtiise when perfect, 

 but often erose or somewhat acute ; the axils are generally broad and 

 rounded, and the segments overlapping upwards, but fi-equently the 

 axils are narrow, the segments linear, and scarcely or not at all over- 

 lapping ; many other varieties occur. Structure consisting of minute 

 vesicles, all more or less coloured, among which are interspersed large 

 empty ones, the miniite cells forming the interstices or walls ; the surface 

 ones being very minute. Tetraspores tripartite or cruciate, arranged in 

 linear bands within the margin, immersed among the surface cells of 

 the frond. Substance somewhat rigid, membranaceous, imperfectly 

 adhering to paper. Colour, a bright permanent red or carmine, 

 becoming rather darker in drying. Tubercles very convex, immersed 

 in simple or compound marginal leaf-like lacinise, with which the 

 segments of the frond, esjjecially towards the base, become fringed. 



This beautiful species so much resembles Nitophyllum in many of its 

 characters, that when less attention was paid to the structure than at 

 present the two were often confounded together, but when the micro- 

 scopical structiire is taken into account, there cannot be the least 

 difficulty in distinguishing the two. 



The curious structure of the frond, which may be said to be vesicular 

 rather than cellular, and the pecixliar arrangement of the spores in 

 separate groups, are its principal distinguishing characteristics. These 

 vesicles are numerous, large, irregularly ovate, and appear to be empty. 



The species is by no means rare on most of our shores, but seems most 

 abundant on the west coasts. On the eastern side of the island we have 

 never observed it growing even on the stems of Laminarice, but it is not 

 unfrequently cast on shore, and sometimes in considerable quantities. 



From its bright colours and somewhat rigid substance it is much sought 

 after by those who collect sea-weeds only for ornamental piu-poses. 



Although subject to considerable variation in form, and in the division 

 of its segments, yet there is something so peculiar in the colom- and 

 structure as well as outline of the frond which prevents it from being 

 readily confounded with any other. 



EXPLANATION OP PLATE LXXXVL 



Fig. 1. — CaUophyllis laciniata, natural size. 

 2. — Portion of frond with tubercle. 

 3. — Section of frond and spores. 

 4. — Portion of frond with, tetraspores. 

 5. — Tetraspores from same. All magnified. 



