8 1 ILLINB \\l> SERVE! . 



Generally characterised by the slenderness and delicacy of all the 

 parts; typical S. Filipendula, stouter ;m<l shorter, with broader and 

 more dentate leaves and more condensed fructification, has qoI I 

 found here. 



7. S. Hystrds •!. G. Agardh, 1847, p. 7: 1889, p. 91, II. VI. Stem 

 terete, smooth; leaves thickish, lanceolate or ovate-lanceolate, entire 

 or obscurely dentate, •'! 6 cm. long, I s nun. wide, midrib rather 

 indistinct, do cryptostomata; vesicles sphericaT, up to 7 nun. diam., 

 pedicel short, sometimes imperceptible; fructification in dense glom- 

 erules of short, verrucose branches; receptacles, vesicles and lei 

 densely packed along the little branched axis. Harris Hay. 1 i 

 attached. Hervey; washed ashore on Avar's and Bethel's Islands 

 after a storm, Dec.. Collins. Apparently recently torn from its 

 attachment. 



While our plant appears to agree in all other respects with S. Hystrix, 

 the receptacles, though quite verrucose, show no spines or teeth. 

 We should hardly have ventured to give it this name, bul for what is 

 said by Reinbold in Weber, 1913, as to sexual dimorphism in Sar- 

 gassum, with presence or absence of spines on the receptacle- accord- 

 ing to sex. We suspect that another instance of dimorphism may be 

 found in S. plaiycarpum Montague and S. mdgare Agardh, at least 



the plant distributed under the latter name as P. B.-A., No. 17^. 



We have seen a large number of plants from Florida, some with smooth, 

 some with spiny receptacles, otherwise indistinguishable. 



8. S. ri.\iY< akimm Montagne var. bebmudense Grunow, 1915, 

 j). 389. We have not seen this, and include it only on the authority 



of Grunow. 



Family DICTYOTACEAE. 

 Spatoglossum Kutzing. 



S. Schboeder] (Mert.) J. G. Agardh, I860, p. 113, in part; 1894, 

 p. 38; P. B.-A., No. 2027; S. Areschougii Vickers. 1905, p. 58; 1908, 

 part [I, p. 38, PI. XI; Ulva Sckroederi Mertens in Martin-. 1826, p. 21; 

 1827, PI. II, 6g. 3; Taonia Sckroederi Parlow in Alg. Am.-Bor. Exsicc., 

 No. 159. Gravelly Bay, Feb., March, Hervey; Gravelly Bay, April. 

 Aug., Cooper's Island, Aug., Collins. Observed only at these two 

 station-, and apparently not common. In the water it shows a l»ril- 

 liant iridescence. Tetraspores, much like those of Dictyota, were 

 found OH a few plants; there d<>c- not seem to have been any previous 



