256 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



tached individually to the surface cells. Sterile specimens are so simple 

 in morphology (unbranched) that at first observation they do not seem 

 to resemble Rhodochorton. 



In D. 381c, Tepoca Bay, February, a itw filaments arising from 

 short, prostrate filaments seem otherwise like this species, though long 

 branching is more frequent. D. & R. 3425d, on Gracilaria, Guaymas, De- 

 cember, is a sterile example of this species. 



A specimen from San Martin Island on the outer coast of Lower 

 California, H. 626, on Cystoseira, resembles this species very closely in 

 general appearance, but was tentatively named Rhodochorton variabile 

 Drew by N. L. Gardner in manuscript. The fragmentary material avail- 

 able seems to indicate a base of creeping filaments and in other respects 

 shows close similarity to D. 381c. These two collections may be mutually 

 identical and yet different from R. Hancockii, but, for the present, mate- 

 rial is not sufficiently ample to make positive determination. All of the 

 plants mentioned here differ from R. variabile in their smaller size and in 

 the more slender, less abundantly branched filaments. The branchlets, 

 moreover, are secund and mostly simple, of about 2 cells ; those of R. vari- 

 abile are pinnate and mostly compound. 



Rhodochorton sinicola sp. nov. 

 Plate 41, Figs. 1, 2 



Frondes epiphyticae, 300-500 n altae, per cellulam basalem multo-dilatatam, 

 afBxae et ex ea filis uno aut multls, prope basim copiose, superne laxe ramosis ori- 

 entibus; ramis cylindricis, 4-5.6 \i diam., cellulis 3-5-aut 6-plo diam. longioribus, 

 compositis; monosporis in ramellis, 2-cellularibus, lateralibus, secundis positis, 11- 

 14 \i longis, ovoideis, uni-et angustiori pedicellatis; spermatangiis prope 4-5 |x 

 longis, laxe et terminali aggregatis in ramellis brevibus lateralibusque, positis. 



Plants epiphytic, 300-500 jtt high, attached by a single, much-enlarged 

 basal cell which may be embedded between the surface cells of the host; 

 basal cell giving rise to from one to several erect filament-axes which 

 branch abundantly near their bases, less frequently above; branches longer 

 above, cylindrical throughout, not markedly attenuated, 4-5.6 fx diam., 

 cells mostly 3-5, or 6 diameters long; chromatophore parietal; asexual 

 reproduction by monospores ; monosporangia borne terminally on usually 

 2-celled lateral secund branchlets, 11-14 /x long, ovoid, the 1-celled pedicel 

 very much smaller in diam.; antheridia in loose, terminal clusters on 

 short, branching lateral branchlets, ellipsoidal, about 4.5 p. long. 



Type: D. 739, on Dictyota, shore of Turner's Island, July 18, 

 1940. Herb. AHF no. 17. 



