CORALLINACEAE. 539 



arid about % line broad and high. Type from Bermuda (Farlow). In \ 

 feet of water at Tucker's Island (Howe). 



Goniolithon intermediSum Fosl. (type from Bermuda, Wadsivorth) differs 

 from the foregoing chiefly in its erect, nearly straight and fastigiate upper 

 branches. In habit it is somewhat intermediate between G. decutescens and 

 G. strictum Fosl. (type from Florida). The G. decutesccns-G. strictum group 

 is widely and numerously represented in the West Indian region and while the 

 plants show great variety in form and size, specific limits, if they exist, are 

 very difficult to define. Furthermore, the plants of this group sometimes 

 make a close approach to the earlier-published Goniolithon frutescens Fosl. 

 from the South Pacific. 



Amphiroa fragilissima Lamour. In both Amphiroa and Corallina, the 

 plant-body is more or less regularly and distinctly jointed, terete or flattened, 

 and di-(tri-)chotomously or pinnately branched. In Corallina, the concep- 

 tacles are terminal; in Amphiroa, they are lateral, on the faces of the seg- 

 ments. Amphiroa fragilissima, as currently interpreted, has a very fragile, 

 terete, repeatedly dichotomous thallus, forming loose or rather compact 

 cushions 1-3 inches high and sometimes one foot or more wide. The segments 

 are mostly T ^-f of a line in diameter and are 4-10 times as long as broad; 

 they often show annular, discoid, or genicular enlargements at the nodes. The 

 branches sometimes taper a little towards the extremities, but, the segments are 

 commonly of a nearly uniform diameter throughout the plant. (Phyc. Bor.- 

 Am. 2198 and 2199). The name of the present species goes back to Corallina 

 fragilissima, L. (Syst. Nat. 1: 806. 1758 ed. 10), which is based essentially 

 on a Jamaican plant figured by Hans Sloane (Hist. Jam. pi. 20. f. 5) a plant, 

 that, so far as may be judged from the description and figure, might as well 

 be a condition of Corallina rubens. Gmelin (Syst. Nat. 1: 3840. 1788) modi- 

 fied and probably changed completely the Linnaean conception of the species, 

 substituting another description and figure of Sloane 's for those cited by 

 Linnaeus, and this modified conception of the species is the one that has been 

 adopted by Lamouroux and subsequent writers. The genus Amphiroa is 

 probably represented in Bermuda by two or three species, but their delimita- 

 tion and correct naming, as is also true of the species of Corallina, awaits a 

 more critical study of their comparative anatomy and of the pertinent historic 

 types. 



Corallina rubens L. is a name in current use for a delicate, jointed, 

 dichotomo-fastigiate plant that forms dense pale red tufts or mats J-H inches 

 high on rocks or on stalks of Sargassum near the low-water mark. The seg- 

 ments are terete throughout or slightly flattened under the dichotomies, Tt-fj 

 of a line in diameter, mostly 3-5 times as long as broad, the apical often 

 taper-pointed. The rather infrequent terminal conceptacles are somewhat flat- 

 tened urn-shaped, the shoulders often produced into a pair of horn-like or 

 antenna-like branches. (Phyc. Bor.-Am. 2200.) 



Corallina pumila (Lamour.) Kiitz. is a name that has been adopted by 

 Collins for a minute coralline that forms tufts a little more than a line high 



