NO. 8 DAWSON : A REVIEW OF THE GENUS RHODYMENIA 135 



(18) RHODYMENIA HOWEANA sp. nov. 



R. corallina Howe, Mar. Alg. Peru (1914), p. 124, pis. 50-51; 



ISphaerococcus palmettoides Bory, Voy. Coquille, Bot. Crypt. 



(1829), p. 173. 



Plate 19, Fig. 9 



Frons usque ad 15 cm. alta, e disco simpHci, stolonibus paucis; stipitibus 

 brevissimis 0.4-0.5 cm., gracilibus superne in laminis copiose dichotomis expansis, 

 merabranaceo-gelatinosis ; segmentis laminarum 1-1.5 cm. longis, 3-5 mm. latis, 

 plus minusve 100 [x crassis, laesis proliferationes angustas apicibus rotundis 

 frequenter emarginatis emittentibus ; marginibus integris ; tetrasporangiis in sori 

 orbicularibus in partes apicales segmentorum sitis et transformationes negligentes 

 stratorum corticalium efficientibus, cruciatis, elongato-ovoideis ; cystocarpiis super 

 superficies medias partes laminarum sparsis, hemisphericis, non-rostratis. 



Fronds membranous-gelatinous, to 15 cm. high from a simple hold- 

 fast with few accessoiy stolons ; subterete portion of stipe very short, 0.4- 

 0.5 cm., slender, expanding into an abundantly dichotomous frond; seg- 

 ments 1-1% cm. long, 3-5 mm. broad, about 100 |i thick, when injured 

 producing narrow proliferations, with rounded apices often conspicuously 

 notched; margins entire; tetraspores in rounded sori in apices of ultimate 

 segments, causing little modification of the cortical layers, cruciate, long- 

 oval ; cystocarps scattered over mid-portions of the fronds, hemispherical, 

 not beaked. 



Sterile and Tetrasporic Types. — In beach drift. La Punta, near Cal- 

 lao, Peru, R. E. Coker # 29 & 30, Jan. 25, 1907. 



Cystocarpic Type. — In the surf, Lobos de Tierra, Peru, R. E. Coker 

 # 149a, April 2, 1907. In Herb. Univ. Calif.: ster. 198881, tetr. 199622, 

 cyst. 199608. All specimens received from Marshall A. Howe. 



Now that the true identity of Rhody/nenia corallina is established and 

 that species is arranged under Sec. Dendry?neniae, it is not at all difficult 

 to distinguish R. Howeana in which, according to Howe, the subterete 

 stipe is only 0.4-0.5 cm. long. The habit of this species is very distinct 

 from R. corallina in the manner of segmentation of the frond as well as 

 in the nature of the stipe. 



(19) RHODYMENIA CALIFORNICA Kylin, Die Florideenord. 

 Rhodymen. (1931), p. 21, fig. 22. 



This is apparently one of the commoner and more variable species 

 along the Californian coast. Kylin describes it very briefly from material 

 collected at Monterey. In the Herbarium of the University of Cali- 

 fornia there are, however, specimens from several localities which indicate 

 something of the variations of the species and allow a fuller account. 



