352 
The species has been found growing on stony bottom in 15—22 meters depth 
in the northern Kattegat and in the Samsø Water and further in the little boat 
harbour at the end of the northern mole in the harbour of Frederikshayn near 
low-water mark. In Herthas Flak it reached a length of 17 cm but was sterile. In 
the harbour of Frederikshayn it attained a length of 10cm and bore abundant 
paraspores, more sparingly tetraspores and dispores. In the other localities the spe- 
cimens were only 1 cm high but fructiferous. The species has only been met with 
in July, September and October. 
Localities. Km: Herthas Flak‘ (FG, XJ) 20 to 22 m; Frederikshavn (only found in 1896 and 
1919); TO, Tonneberg Banke 18 m; iG, 3 miles W. of Læso Trindel light-ship, 15 m (+ 10). — Sa: 
MS, near Endelave, 15 m, with paraspores. 
Plumaria Stackhouse, emend. Schmitz. 
Euptilota Cramer. 
1. Plumaria elegans (Bonnem.) Schmitz. 
Fr. Schmitz, Systemat. Uebersicht, Flora 1889, reprint p. 16; Phillips 1897, p. 361, pl. 18 fig. 17; Kol- 
derup Rosenvinge 1911 p. 210; Kylin 1923, p. 57. 
Ptilota elegans Bonnemaison, Hydrophytes loculées ou articulées. Paris 1828. (Not seen). J. Agardh 1851, 
p- 94; Kützing, Tab. phyc. 12. Bd. 1862, Taf. 56; Pringsheim 1862, p. 32, Taf. 8 Figs. 2—7; Bornet 
et Thuret, Notes algol. Fasc. I 1876 p. XV: Farlow, Mar. Alg. New Engl. 1881 p. 133; Buffham 
1884 p. 342, 1891 p. 247, 1893 p. 303; Wille, Physiol. Gewebesyst. 1887 p. 72 Tab. IV Figs. 42, 43, 
Tab. VII Figs. 40, 41. 
Ptilota plumosa ; tenuissima C. Agardh 1822 p. 386; Nageli 1847 p. 206, Tab. VI figs. 3842; Areschoug 
1850 p. 97. 
Ptilota sericea (Gmel.) Harvey Phyc. Brit. Vol. II 1849 Plate 191. 
Ptilota plumosa Cramer 1864 p. 6, 108, Taf. I Figs. 4—5 Tab. II Figs. 1—5, Tab. III Figs. 1—3. 
The structure and development of the frond has been carefully described by 
NAGELI (1847) and Cramer (1864) whose papers may here be referred to.” The 
longer primary shoots are alternating, being usually separated by two joints. 
There is no distinct limit between the pinnæ with persisting growth and the pinnule 
with limited growth. The ramification of the feebler pinne is less regular than 
that of the vigorous ones. The young branches are more or less curyed inwards, 
in particular in the most vigorous shoots. Most of the branches become short plumose 
pinnulz persisting in the older parts of the frond. The frond is sometimes not plane 
but vaulted, all the tips of the frond being directed to the same side. The convex 
side seems then to be directed towards the incident light. 
* In my paper 1911, p. 205, a sterile specimen of Seirospora Griffithsiana has erroneously been 
recorded as Griffithsia setacea. 
> OLrmanxs has not noticed the puzzling synonymy of this species caused by CraMER’s unlucky 
denomination; he has therefore been misled into confounding the genera Ptilofa and Plumaria and has 
in Morph. u. Biol. d. Algen I Fig. 364 under the name of Ptilota plumosa reproduced figures both of 
this species (figs. 1, 4) and of Plumaria elegans (figs. 2—3). Comp. Kylin 1923, p. 57. 
