298 
Spermothamnion Aresch. 
1. Spermothamnion repens (Dillw.) K. Rosenv. 
Conferva repens Dillwyn, Brit. Conferv. pl. 18 (fasc. 2, 1802 (?)). 
Ceramium Turneri Mertens in Roth, Catalecta botan., III, 1806, p. 127, Taf. V. 
Conferva Turneri Dillwyn, Brit. Conf. PI. 100, 1809. 
Callithamnion repens Lyngbye, 1819, p. 128, Tab. 40; Kützing, Tab. phyc. XI Tab. 69 I. 
Callithamnion Turneri (Roth) C. Agardh, 1828, p. 160. J. Agardh, 1851, p. 23. Harvey, Phyc. Brit. I, 
pl. 179. Kützing Tab. phyc. XI Tab. 80. 
Callithamnion roseolum C. Agardh, 1828, p. 182. J. Agardh, 1851, p. 21. 
Ceramium roseolum (C. Agardh) Hornemann, Flora Danica Tab. 2262, 1, 1839. 
Spermothamnion Turneri (Mert.) Aresch., 1850, p. 113 (with «, Turneri, ?, roseolum and 7, repens). 
Bornet et Thuret, Notes algol. fasc. I, 1876, p. 24, pl. VIII figs. 4—5. Hauck, Meeresalg. p. 42. 
Spermothamnion roseolum (Ag.) Pringsheim, 1862, p. 15, Taf. IV—VI. Hauck, Meeresalg. p. 44. Reinke 
Algenfl. 1889, p. 22. H. Kylin, Über Spermothamnion roseolum (Ag.) Pringsh. und Trailliella intricata 
Batt., Botan. Notiser 1916. Id. 1923 p. 53. 
Herpothamnion Turneri (Mert.) Nägeli, 1861, p. 348, figs. 14—16 and 18—19. 
Herpothamnion hermaphroditum Nägeli, ibid. p. 352, figs. 28—29. 
Spermothamnion hermaphroditum (Näg.) Janczewski, Développement du cystocarpe d. 1. Floridées. Mem. 
Soc. sc. nat. de Cherbourg. Vol. XX, 1877, p. 115, pl. 3, figs. 7—14. 
«, Turneri (Mertens). 
Branches generally opposite, the tetrasporangia usually in corymbiform clusters. 
Sexual organs usually present. 
8, roseolum (Agardh). 
Branches generally alternate, the tetrasporangia single or in pairs (small 
clusters). Sexual organs frequently wanting. 
Various opinions as to the denomination and the limitation of this species are 
still maintained. British authors mention Spermothamnion Turneri as common on 
the British shores but do not mention Sp. roseolum as a distinct species occurring 
there. On the other hand, C. Acarpn and J. ÅGARDH designate by this latter name 
the species occurring on the western coast of Sweden which they consider different 
from S. Turneri, a species which they do not record from the Swedish coast. KyLın 
follows them in 1907 (Stud. Algenfl. schwed. Westk., p. 149). J. AGARDH (Spec. g. ord. 
II, 1, 1851, p. 24) quotes the characters by which Callithamnion roseolum differs 
from C. Turneri, viz. the ramification which is more rarely opposite, the sporangia 
which are single or placed in pairs while they are aggregate in C. Turneri, the looser 
and often- longer tufts and the longer cells. These characters are, however, very 
variable, of which one is easily convinced by examination of a greater number 
of specimens. I can therefore only approve that J. ARESCHOUG in 1850 referred 
Call. roseolum as a variety under Spermothamnion Turneri, and it must also be 
considered that he is justified in referring Conferva repens Dillw. to the same species. 
- Comp. ScamiTz in Hauck et RICHTER, Phycotheca universalis No. 657, 1895. 
