478 BULLETIN OF THE BUREAU OF FISHERIES. 
when exposed to similar ice scraping and shows clearly why the littoral flora in mid- 
winter is so little developed in this region. Returning to chart 267, it will be seen that 
the alge were all below low-water mark, the most conspicuous forms being Ceramium 
rubrum (43) and Chondrus crispus (49), forming a zone around the rocks. 
The group of rocks a month later presented a very different aspect, as shown in 
chart 268, recorded on April 22. Cladophora lanosa var. wncialis (11) had appeared in 
considerable quantity near low-water mark. and somewhat lower down was an imperfect 
zone consisting of young growth of Phyllitis fascia (24) and Scytosiphon lomentarius (26). 
Polysiphonia urceolata (47) had appeared well below low-water mark and was the most 
conspicuous member of a zone of red alge, including Ceramium rubrum (43) and Chondrus 
crispus (49). There were present Sorocarpus uveformis, four species of Ectocarpus, and 
the two species of Desmotrichum, all new to the rocks, showing how quickly such alge, 
reproducing by zoospores, may establish themselves. A notably new form was Chorda 
tomentosa (32), which had begun to appear. 
Chart 269, recorded May 22, shows the conditions after another month, and when the 
spring flora was at its full development. Cladophora lanosa var. wncialis (11) was still 
the dominant green alga, but Enteromorpha intestinalis (7) had begun to appear, and these 
two alge had extended the green zone much higher on the rocks than at the previous 
date, April 22 (chart 268). The brown zone at low-water mark, composed chiefly of 
Ectocarpus penicilatus (18), Phyllitis fascia (24), Scytosuphon lomentarius (26), and 
Chordaria flagellijormis (28), was much more evident. Polysitphonia urceolata (47) was 
very conspicuous in the zone of red alge below the brown. Chorda tomentosa (32) was 
abundant. 
Conditions were very greatly changed after another month, as shown in chart 270, 
recorded June 29, the spring flora having given place to the beginning of the summer 
flora. Cladophora lanosa var. uncialis had entirely disappeared, and the prominent 
green zone above low-water mark was composed of Ulothrix implexa (3) and Enteromorpha 
intestinalis (7), with young growths of Ulva Lactuca var. rigida (5). The brown zone 
near low-water mark was now chiefly Scytostphon lomentarius (26) and Chordaria flagel- 
liformis (28); Phyllitis fascia was represented by only a few old plants and Ectocarpus 
penicillatus had disappeared. The other species of Ectocarpus, Desmotrichum, and 
Sorocarpus uveformis, as well as Chorda tomentosa, were also no longer present. Polysi- 
phonia urceolata had disappeared, its place being taken by Polysiphomia violacea (48), 
which with Ceramium rubrum (43) and Chondrus crispus (49) chiefly composed the zone 
of red alge below the brown zone. Nemalion multifidum (40), a characteristic summer 
species, had begun to appear at and above low-water mark. 
The typical summer flora is shown on chart 271, recorded July 22. The conspicuous 
green alga was Ulva Lactuca var. rigida (5), growing in large patches with other green 
alge in small quantities. There was a well-defined brown zone just above low water 
composed chiefly of Chordaria flagellifornis (28) and Scytostphon lomentarius (26), both 
bearing Ectocarpus confervoides (14) as a conspicuous epiphyte; Phyllitis fascia had dis- 
appeared. Nemalion multifidum (40) was now plentiful, fringing the rocks at low-water 
mark. Below the brown zone and mixed with it were abundant growths of Ceramium 
rubrum (43), Polysiphonia violacea (48), and Chondrus crispus (49). Chart 272, recorded 
September 2, is similar to chart 271, but with certain features more pronounced. The most 
