491 



Mv reason for regarding this ns an independent variety, instead 

 of including il under var. micrpcocca, which Hauck, e. g. ( Die 

 Meeresalgen Deutschlands und Oesterreich«, p. 432) points oul as 

 perhaps the most correct course, is that I have found quite typical 

 specimens ol' il, although not in any great number. This variely 

 as already mentioned under var. micrococca is otherwise intimately 

 connected with the latter through intermediate forms. 



var. compressa (L.) Rosen v. 1. c. p. 958; Ulva enteromorpha f}, 

 compressa Le Jolis, Liste, p. 44; Scytosiphon compressus Lyngbye, 

 Hydrophyt., p. 04, ex parte. 



Some of the specimens referred to this variely are almost 

 branchless, though branching or prolific specimens have also been 

 found. Some of these are somewhat similar to f. complanata. 

 OtherSj more richly ramified, closelv resembled in habit E. clathrata, 

 from which species they mav generally l)c distinguished, as pointed 

 out, e. g. by Reinbold, by the faet that the cells of E. clathrata 

 are arranged in rows; it must, however, he horne in mind, that 

 this character cannot always be applied, as I have found specimens 

 in which the cells in the same individual were sometimes in rows, 

 and sometimes without any arrangement whatever, in faet every 

 degree of development exist in the arrangement of the cells. A 

 transverse section of the typically developed plant shows the inner 

 wall lo be thin while through others may be traced a quite gradual 

 transition to the more or less thickened inner wall of E. intestinalis. 



Of var. compressa, I have found a formå trabeculata, which 

 exactly resembles that which Rosenvinge (1. c. p. 961) has des- 

 cribed under E. prolifera. The specimens were found in tide-pools 

 near high-water mark on the west coast of Stromo near Velheslad, 

 and they could be seen by the naked eye, as the plant when alive 

 almost resembled a Chaetomorpha. As pointed out by Rosen- 

 vinge, complete partition-walls were not to he found here cither, 

 but merely piates or trabeculæ more or less irregularly extended 

 in transverse and oblique direclions. The thickness of the trabe- 

 culæ is very slight, and, as slated by Ro se uvinge, they tnrn 

 yellow when stained by chlor-zinc-iodine. I think that a specimen in 

 Lyngbye's Herbarium, cailed by him Scytosiphon coinj)rcssus, 

 mav be referred to this variety; another from Næs, Østero, has a 

 rather Ihick inner wall, and must therefore be regarded as belonging 

 to var. genuina. 



var. prolifera (O. F. Muller); Enteromorpha prolifera (O. F. Muller) 



