534 GRATELOrPIACEAE. 



of the inner cells of the subcortex are seen to be enlarged, subglobose, echinate- 

 stelliform, projecting into the medullary cavity, and showing when detached 

 15-40 rather rigid subspinescent processes. Known only from a specimen 

 dredged in '*31 fathoms, off Bermuda" by members of the Challenger Expe- 

 dition in 1873. Apparently endemic. 



Halymenia Agardhii De-Toni, has, in its Bermuda forms, a soft, dark red, 

 subterete, repeatedly dichotomous, more or less gelatinous frqnd that is 3-4 

 inches long (commonly longer in Florida and the West Indies), with segments 

 i-i of an inch broad. The only known Bermuda alga with which it might 

 possibly be confused is a species of N emastoma, from which it differs in its 

 darker red color, in its more regular dichotomy, in being less lubricous, and, 

 microscopically, in its firmer, more pseudoparenchymatous, less obviously fila- 

 mentous cortex, and the frequent anastomoses or small nodal ganglia among 

 the medullary filaments. The plant has been found washed ashore on .South 

 Beach and growing attached to rocks near low-water mark at Gibbet Island. 



Cryptonemia crenulata (J. Ag.) J. Ag. apparently occurs in Bermuda 

 (_on sand-covered rocks in a cave. Gravelly Bay, Hervey) in a small reduced 

 form, and possibly better-developed conditions are yet to be found in deeper 

 water, where it may be expected on the bases of sea-fans, dead-men 's-fingers, 

 etc. As thus far found, it has a sparingly dichotomous rose-purple mem- 

 branous frond 1-2 inches long, from a subterete stipe. The main divisions are 

 about K of an inch wide, strap-shaped or cuneate-ligulate, often stipitate, sub- 

 entire, occasionally with small ovate or suborbicular stipitate innovations. In 

 normal forms of the species, the segments are i-| inch broad and have crenu- 

 late-denticulate margins, the teeth often bifid or trifid or furnished with a 

 small crown of secondary teeth, (Phyc. Bor.-Am. 2100.) 



Cryptonemia luxurians (Ag.) J. Ag. differs from the foregoing in having 

 a caulescent, costate-alate frond, the costa vanishing towards the apices. The 

 only Bermuda specimen seen is about 4 inches tall, several times dichotomous, 

 the segments i-4 inch broad. On rocks in shallow water at Red Bay, St. 

 David's Island {Howe 287). 



Family DUMONTIACEAE. 



Dudresnaya crassa M. A. Howe, is a flaccid extremely lubricous densely 

 ramose dioicous plant that is 2—6 inches high or long and rose-colored when 

 living, though commonly dingy purple or brownish red on drying. In the 

 pressed and dried condition, the branching appears to be irregularly 2-3-pin- 

 nate, though the branches really emerge in all directions ; branches and branch- 

 lets are vermiform, of nearly uniform diameter throughout; the ultimate 

 branchlets are obtuse or subobtuse and mostly -^-§ of a line in diameter. 

 Under a microscope the very soft gelatinous cortex is seen to be made up of 

 essentially free, 4—6 times dichotomous, beautifully fastigiate cylindrie fila- 

 ments, the more peripheral cells of which are 2-5 times as long as broad. In 

 the younger parts, the central axis, consisting of a single row of cells, bearing 

 the crowded whorls of peripheral filaments may be readily seen ; in the older 



