220 KJELLMAN, THE ALG^ OF THE ARCTIC SEA. 



However, the proper season for producing zoospores appears to be later, probably in 

 the month of June. 



Geogr. Distrib. At present this species is known with certainty in the Arctic 

 Sea only from the eastern part of the Siberian Sea. Here it was everywhere found 

 abundant. 



Localities: The Siberian Sea: Koljushin Isle, and at two places eastward of the 

 mouth of Koljushin Bay, abundant. 



The American Arctic Sea: the north coast of Western Eskimaux-land (?). 



Alaria oblonga nob. 



A. stipite perbrevi, vix ultra poUicari, terete; rhachide demum pluripoUicari, apicein versus incrassata, 

 compressa, in sectione transversali elliptica, residuis spoiophyllorum abjectorum in plantis senilibus longe deorsum 

 plus minus distincte muriculata, abrupte in costani abeunle; lamina elongata, lineari-oblonga, basi ovata, vix 

 decurrente vel ovato-cordata, usque 25 cm. lata, tenue membranacea, unduiata: costa prominula, in sectione 

 transversali elliptica; sporophyllis numerosis, subdistantibus, petiolatis, lanceolato-spatliulatis, angustis 1,5 — 2 cm. 

 latis, sterilibus tenue membranaceis, parte fertili subpergameis, marginc uudulato-crispatis, longe infra apicem 

 sorum formantibus. Tab. 22 at 25 fig. 21 — 24. 



Description. The rhizines issue in alternate whorls and are subdichotomously 

 branched. The branches in the present species as in other Laniinariaceae are shorter 

 and more robust as the substratum is more solid. 



The stipe is very short, sometimes almost imperceptible, on account of the cauloid 

 portion bearing or, as is shown by the cicatrices, having borne sporophylls immediately 

 above the rhizines. Its length in older individuals usually varies between 0,5 and 2 

 cm. In very young individuals the stipal part may be distinguished from the rhachis 

 by the latter being thicker. In very old specimens the limit between these two parts 

 of the cauloid portion is indistinct on account of the cicatrices of the fallen first sporo- 

 phylls being effaced. In outline the stipe is terete downwards, somewhat, but only slightly, 

 compressed upwards, where it passes into the rhachis. In the oldest individuals I met 

 with, the stipe was 5 mm. in diameter. 



The rhachis increases in length as the plant grows older, attaining a length of at 

 least 14 cm. It is almost terete downwards, but upwards it is flattened and thicker. 

 Above the uppermost sporophylls it tapers swiftly, soon passing into the costa. The 

 part with sporophylls is flatly elliptical in profile, at least 8 mm. in its longest dia- 

 meter. The difference in shape and thickness between the stipe and the rhachis in the 

 same individual is shown by fig. 21 and 22 in tab. 25. 



The lamina, as shown by the figures of tab. 22, in younger as well as older 

 specimens has almost perfectly the same shape, elongatedly linear-oblong, or in other 

 words linear-lanceolate, with rounded base which is not at all or almost imperceptibly 

 decurrent. It sometimes tapers towards its extremity somewhat more swiftly and 

 strongly than in the specimens delineated, and sometimes in very old specimens the 

 base is almost cordate. The lamina attains a considerable size, but it is only seldom 

 that a specimen is found with the whole lamina preserved. In my collections I have 



