279 



It can support a strong surf and is then living in much polkited water. It attains 

 a length of 15 cm in the Skagerak, 8 cm in the Linifjord. It has only been collec- 

 ted in June to August. Nearly all the specimens bore cystocarpia. It has only been 

 found in the sal test waters. 



Localities. Sk : YN, within Bragerne, 5 m; washed ashore on Granliej Strand (Miss Ellen 

 Mailer); Hirshals, mole and reefs, 1 — 5 m. — • Lf : Sallingsund, near Nykabing, east side of Odden (Th. 

 Mortensen, !) and off Grennerup. In the herbarium of the Botan. Museum at Copenhagen a specimen 

 is to be found, labelled Limfjorden Aug. 1869, probably collected by J. P. Jacobsen. 



Some general remarks on the Cryptonemiales. 



1. Intercalary cell-divisions. The species belonging to this order appear as 

 a rule to follow with great regularity the rule pointed out by Schmitz ^) for cell- 

 division in Florideae: that only the terminal cells in the filaments, of which the 

 frond is composed, divide by transverse walls. Some cases occur, however, where 

 transverse divisions of the segment cells have been noted. Thus, according to 

 Brebner, intercalary transverse divisions take place in Duinontia incrassata in the 

 short-celled filaments, which grow out from the basal disc and form the upright 

 fronds (see above p. 156). Another instance 1 have noticed in Hildenbrandia prototypus, 

 where intercalary divisions may occur in the radiating filaments forming the 

 basal layer, which makes itself apparent in the fact that the cells are shorter at 

 some distance from the margin than at the margin itself (p. 203 fig. 121). It should 

 further be mentioned, that the filaments in several Melobesiese (Lithothamnion, 

 Corallina) terminate in a covering cell, which does not divide, and which forms, 

 together with the covering cells of the adjacent filaments, an outer layer, incapable 

 of development, the penultimate cell in the filament taking over the function of 

 the terminal cell as an initial one. A deviation from the order of succession in 

 cell division as noted by Schmitz may also be found in some species of Melobesia 

 and Lithophyllam, where two or more cortical cells, likewise incapable of division, 

 are cut off one below the other at the end of the same mother cell (p. 254 fig. 174 

 and p. 264 fig. 184 B) 2). 



2. Cell-fusions. Secondary pits, which are commonly found in the Rhodo- 

 melacese and several other families of the Floridese ') appear to be altogether lacking 

 in most Cryptonemiales. I have only found them in the genus Lithophyllam, As 



') Fr. Schmitz, Untersuch. iiber die Befrucht. d. Florideen. Sitzungsber. d. Ak. d. Wiss. Berlin 

 1883, p. 216. 



^) Intercalary divisions appear to occur throughout the whole of the frond, at any rate in the 

 perithallium in the genus Porolithon, to judge from the drawings of Mme Lemoine in Borgesen, The 

 Marine Algae of the Danish West Indies, III Rhodophyceae. Dansk Botanisk Arkiv. II p. 177 and p. 17i). 



^) Gomp. L. KoLDERUP Rosenvinge, Sur la formation des pores secondaires chez les Polysiphonia. 

 Botan. Tidsskr. 17. Bind. Kjabenhavn, 1888, p. 10. 



