Warner: observations on endocladia muricata. 299 



lateral. We have found both sorts on the same plant so it has 

 seemed best to include both under the same name" — Setchell and 

 Gardner. This is true also of the specimens examined by me. 



Endocladia muricata (P. and R.) J. Ag. is a red alga belong- 

 ing to the genus Gigartinacere. The plants studied at the 

 Minnesota Seaside Station, Vancouver island, seem to be the 

 typical form. Setchell and Gardner describe two other forms, 

 E. muricata forma comftrcssa and forma inermis, but as the 

 specimens in hand have not a particularly flattened frond and 

 are not destitute of spines, they are probably neither of these 

 forms. 



The plants were found growing on rocks and boulders in the 

 upper portion of the littoral zone very near high water mark. 

 They were fastened quite firmly to the substratum. The fronds 

 are low, from 2-4 cm. in height, shrubby in appearance, and 

 very dark red or brown in color. The branching is dense and 

 irregular and the branches are profusely covered with spines. 

 The frond seems to proceed from a branch which runs hori- 

 zontally along the surface of the substratum. This horizontal 

 branch sends off downward branches at the ends of which hold- 

 fasts are developed. Upright branches develop into the 

 frond. 



Frond. — Examining a longitudinal section {Plate XL VI., jig. 

 4) of the frond a conspicuous central cylinder is seen surrounded 

 by a mucilaginous sheath. This axis is divided into cells about 

 three times as long as broad. There appear to be protoplasmic 

 connections running through the dividing cell walls of the axis 

 cylinder. Branches are given off quite regularly from this 

 central axis, the branches arising just below the cross walls of 

 the central axis, and of ten from two sides of these cells. These 

 branching filaments do not extend radially out to the cortex as 

 described by Harvey, but rather diagonally upward and outward, 

 terminating in the cortex opposite the lower part of the third cell 

 of the central axis from which they started {Plate XL VI. ,Jig . ./). 

 The branching seems to be more or less regular (Plate XL VI., 

 fig. 2). Two branches are given off from the upper third 

 of the cell, following somewhat the method of branching of the 

 central cylinder. The branching, in this way, seems to be quite 

 regular for about eight cells, when it sends off two branches, 

 each of these branching dichotomously until the cortex is 

 reached. There are, however, exceptions to this rule. 



