82 CORALLINACEiE. v. 



opinion rendered more probable by their position, which is the same as that of the 

 fertile bra,nchlets. 



The conceptaclea in the Corallineas are either formed out of the terminal articula- 

 tions of the lesser branches, as in CoraUina and Jania ; or on some part of the 

 surface of the middle and lower articalations, as in Amphiroa. But frequently- 

 spurious conceptacles, equally furnished with spore-threads as the normal ones, 

 sprout out irregularly from any part of the stem or branch. This I have re- 

 peatedly observed in CoraUina squamata and C. officinalis, whose whole surface is 

 sometimes densely warted with such irregular fructification. 



The Corallinacea^, under some form or other, are dispersed through most parts of 

 the ocean, and at depths varying froin the highest level of ordinary tides to many 

 fathoms below low-water mark. The crustaceous kinds in particular abound on 

 the stones and in shallow places, where, however, they seldom exhibit more than 

 an expanded crust. Within the tidal limits, from the level of half-tide to low-water 

 mark, they flourish, fruiting abundantly. Beyond the tidal limit, in water of 5, 10, 

 15, or even 50 fathoms in depth, they are still numerous, and frequently constitute 

 vast banks, made up of unattached fronds heaped together without order, of which 

 those alone on the surface of the bank are in a vegetating state. In such places, 

 though the frond is very luxuriant, fructification is seldom formed. It is extremely 

 probable that many of tliese deep-water forms, now regarded as specifically diiferent 

 from those found within tide marks, are merely barren varieties of the tidal species, 

 altered by a different locality. The true corallines are very x'are in the colder sea, 

 in which alone C. officinalis attains a very high latitude. They are more abundant 

 towards the tropics, and seem to be pai'ticularly numerous and beautiful on the 

 shores of the Australian continent. As yet we can claim few within the limits of 

 the North American Flora, but probably when the Pacific coast shall have been 

 explored many new species will reward the collector. On the whole, the order is 

 greatly moi'e numerous in the Pacific than in the Atlantic Ocean. 



Until recently the Corallinacece, and other calcareous Algae, such as Halimeda, 

 were confounded with the polypiferous Zoophytes, with which division of the 

 animal kingdom they had been united by Ellis, who, nevertheless, figures the 

 spore-threads of C. officinalis with his usual care. 



SYNOPSIS OF THE NORTH AMERICAN GENERA. 



Sub-order 1. Corallines. Frvnd filiform, pinnate or dichotomous, jointed. 

 I CoRALLiNA. Conceptacles terminal, urceolate, simple. Frond pinnated. 



II. Jania. Conceptacles terminal or axillary, turbinate, tipped with two horn-like 

 ramuli. (Frond in our species dichotomous.) 



III. Amphiroa. Conceptacles conical, scattered on the surface of the middle and 

 lower articulations. 



