XXIV. OBSERVATIONS ON CALLYMENIA PHYL- 

 LOPHORA J. AG. 



Clara K. Leavitt. 



Material. 



This study was made from plants collected by the writer in 

 July and August, 1901 and 1902, and by Miss J. E. Tilden in 

 December, 1901 at the Minnesota Seaside Station, Port Ren- 

 frew, B. C. All the older plants were washed up on shore. 

 Only very small young plants were collected on the rocks at 

 low tide. 



Habitat. 



The plant is elittoral. It occurs in crevices in the rocky cav- 

 erns where the surge is strong as the tide runs in and out. It 

 grows in large quantities on the rocks running out from John- 

 son's Cove and is always to be found in the wash in the cove. 

 It is also attached to rocks on the sea bottom and was sometimes 

 washed in attached to the holdfast of a JVereocystis. Only 

 young plants were uncovered by the low tides ( — 1.2 ft.) of 

 August 2-4, 1902. The mature plants were well out beyond 

 the low tide line, indicating that the conditions were more 

 favorable at the lower points. 



Gross Structure. 

 The young plant consists of a small disk-shaped holdfast, a 

 short cylindrical stipe and one or sometimes two, entire some- 

 what circular laminae {Jig- 1). As the plant grows older pro- 

 liferations appear on the margin of the lamina, each consisting 

 of a short cylindrical stipe and a broad, flat, usually oval blade. 

 The main central lamina later becomes thickened longitudinally 

 from the secondary stipes on the margin to the main stipe, form- 

 ing a sort of palmate veining (Jig. 2). A tearing of the lamina 

 between the " veins " results, and the stipe appears to have sev- 

 eral laminae arising from it, where originally there was but one. 

 Often several laminae arise from one holdfast each on a dis- 

 tinct stipe. The older primary fronds are dark red in color, 

 thick, coarse and leathery, while the 3'ounger laminae are much 



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