54° 



BULLETIN OF THE BUREAU OF FISHERIES. 



33 \«** 



Chart 270. — Distribution of algae on Spindle Rocks, June 29, 1905. 



The character of the vegetation on the rocks had greatly changed from that of May 22 (chart 269), 

 and marked the beginning of the characteristic summer flora and the end of the spring season. A green 

 zone on the upper parts of the rocks was composed chiefly of Ulothrix implexa (3), Ulva Lactuca var. 

 rigida (5), and Enteromorpha intestinalis (7); Cladophora lanosa var. uncialis, formerly so abundant 

 and conspicuous, had entirely disappeared. The brown zone near low-water mark (the dotted line) 

 was composed almost entirely of Scytosiphon lomentarius (26), and Chordaria flagelliformis (28); Phyllitis 

 fascia (24) was only represented by a few old plants, and Ectocarpus penicillatus had disappeared. Poly- 

 siphonia urceolata, so plentiful throughout the spring, was no longer present, but Polysiphonia violacea 

 (48) was abundant and with Ceramium rubrum (43) formed a fringe around the rocks a little below low- 

 water mark with Chondrus crispus (49) in deeper water. Nemalion multifidum (40) had begun to appear 

 at and above low-water mark. 



List of algae: Calothrix scopulorum, 1, in small patches; Ulothrix implexa, 3, covering the top of 

 III, VI, and Pyramid Rock; Ulva Lactuca var. rigida, 5, abundant young growths; Enteromorpha intesti- 

 nalis, 7, much; Codiolum gregarium, 10, abundant on barnacles; Phyllitis fascia, 24, few old plants; 

 Punctaria plantaginea , 25, few; Scytosiphon lomentarius, 26, abundant; Chordaria flagelliformis , 28, very 

 abundant; Chorda filum, 31; Laminaria Agardhii, 33, scattered plants; Laminaria Agardhii var. vittata, 

 34, small group; Nemalion multifidum, 40, young growth; Ceramium rubrum, 43, few; Polysiphonia 

 violacea, 48, abundant; Chondrus crispus, 49, abundant. 



