528 CEEAMIACEAE. 



foregoing species, but it differs from that and the other Bermudian species 

 of Callithamnion here mentioned in having the main axes essentially uncor- 

 ticated, though the extreme base of the Bermudian plant is more or less 

 felted with both adherent and free rhizoids. The cells in the basal parts are 

 short, being about as broad as long. The type of the species was from the 

 Danish West Indies and the specific name was given in allusion to the cordate 

 geminate cystocarps. The Bermudian plants seen by the writer are apparently 

 sterile. The ultimate ramelli would seem to be stouter and less abruptly 

 tapering than in the type as figured by B^rgesen. 



Callithamnion Herveyi M. A. Howe, sp. nov. Plants dingy purple, sub- 

 fuscous in age, gelatinous, forming tufts or cushions 2-4 cm. high, ramifica- 

 tion densely and repeatedly decompound, for the most part irregular or ob- 

 scurely tetrastichous, the ultimate ramelli more or less subdistichous or 

 dichotomo-distiehous; main axes with rhizoidal cortications for three fourths 

 or more of their length, 0.3-0.35 mm. in diameter at base and in older parts 

 loosely hirto-tomentulose with simple or irregularly branched rhizoidal 

 ramelli; cells of the largest uncorticated branches 40-80 fj, in diameter, sub- 

 cylindric, mostly 14-2 times as long as broad, their walls 12-25 /JL thick ; ante- 

 penultimate ramuli cylindric-plumose, mostly 0.8-1.5 mm. long, and, with the 

 patent or ereclo ; patent ramelli, 0.3-0.6 mm. brcfad; cells of the ultimate 

 ramelli 1^-2 (rarely 3) times as long as broad, the terminal obtuse, 8-12 fj, in 

 diameter, occasionally piliferous; dioicous; antheridia subglobose or sub- 

 hemispheric, 30-50 /u. in diameter, usually crowning a short but manifest one- 

 celled pedicel ; cystocarps subglobose, 100-220 /j. in diameter, scarcely lobed, 

 often geminate; tetrasporangia lateral, mostly solitary, irregularly scattered 

 or occasionally subsecund, obovoid or subglobose, mostly 38-40 /u. in maximum 

 diameter, tetrahedrally divided or spores sometimes subdecussately paired ; 

 monosporangia terminal, frequent on cystocarpic plants, occasional on anthe- 

 ridial and tetrasporic plants, scattered or irregularly clustered, solitary, some- 

 times concatenate in twos (very rarely in threes), obovoid, ellipsoid, pyriform, 

 or subglobose, 36-65 /JL in longer liameter. [Phye. Bor.-Am. 2046 as Cal- 

 lithamnion Hoolceri (Dillw.) Ag.] 



Type from Smith's Bay, December, 1913, communicated by F. S. Collins 

 as no. 8005, and preserved in the herbarium of the New York Botanical 

 Garden. The species is named in honor of Eev. Dr. A. B. Hervey, author of 

 the popular book, "Sea Mosses," and successful investigator of the marine 

 flora of Bermuda. 



Callithamnion Nerveyi is perhaps most nearly related to the European 

 C. HooJceri, but manifestly differs in its smaller size, in its denser, more 

 cylindric-plumose or tetrastichous, less distichous ramification, in its more hir- 

 tulous-tomentulose main axes, in its more slender and delicate ultimate 

 ramelli (terminal cells averaging about one half the diameter of those of C. 

 HooTceri}, in its much smaller tetrasporangia (averaging about one half the 

 diameter of those of C. Hookeri), in the frequent presence of monosporangia, 

 etc. The plants are often much encrusted with diatoms of various kinds, and 

 even when virtually free from diatoms, the plants collect and hold quantities 

 of fine sand, indicating the presence of a remarkable amount of mucus. The 

 cystocarp has no involucre and conforms to the Callithamnion type not to 

 that of Seirospora. All of the cells except the youngest appear to be pluri- 

 nuclear. The species is endemic so far as known. 



