120 Puget Sound Marine Sta. Pub. Vol. 1, No. 12 



parts, the mucrons are either short and acute, or rounded, or absent en- 

 tirely ; it must be concluded that the above descriptions do not establish 

 two varieties. For example, two plants were found which upon super- 

 ficial examination revealed only utricles without mucrons. It was con- 

 cluded that a variety different from C. mucronatum Californicum had in- 

 deed been found, but further examination of all parts of the frond proved 

 it to be the same variety for the youngest utricles had the conspicuous 

 tj^pical mucron. Another specimen, in the herbarium of the Puget Sound 

 Marine Station, determined by N. L. Gardner as C. mucronaturn Cali- 

 fornicum, if classified according to Collins, would fall under f. Novae 

 Zelandiae, for only very short mucrons or none at all were found on the 

 utricles. 



The similarity between the utricles of the older parts of the fronds 

 of C. mucronatum and those of the mucronless C. tomentosum is perhaps 

 the chief cause of the common confusion of the two. A specimen of the 

 latter species from Algiers, secured through the kindness of Dr. G. W. 

 Farlow of Harvard University, was examined in various parts to see if it 

 really differed from C. mucronatum. No mucrons were found on any of 

 the utricles either young or old, proving it to be indeed different. Falk- 

 enberg (8) says that the characteristics of C. tomentosum fail to separate 

 it from C. elongatum. It is interesting to note in this connection that 

 Svedelius (18) reports it impossible to distinguish between C. mucronatum 

 Californicum and the third variety, named by Agardh (1) C. mucronatum 

 tasmanicum on the basis of a supposedly different type of mucron. 



This study leads the writer to suggest the following description for 

 C mucronatum J. G. Ag. : 



Plant body dark green, consisting of cylindrical, dichotomously 

 branched fronds growing from a horizontal, irregularly expanded holdfast- 

 cushion; both fronds and holdfast-cushion consisting of continuous, branch- 

 ing and interwoven, hypha-like, pith-filaments, from which club-shaped 

 branches (utricles) each originally terminating a pith-filament extend per- 

 pendicularly to the surface, forming a compact cortex ; individual filaments 

 expanded at the base to form holdfasts; utricles clavate-cylindrical, .15-. 35 

 mm. in diameter, .9-1.5 mm. in length, usually with thick-walled, mu- 

 cronate tips ; plugs functioning as cross-walls dividing the pith-filaments 

 into compartments and separating the gametangia and sometimes the utricle 

 hairs from the utricle; utricle hairs sometimes present; large green female 

 (?) gametes 13-16 /a in diameter, borne in ovate gametangia 75-150 jx in 

 diameter and 250-450 pi in length; 1-3 gametangia arising just above mid- 

 dle point of each reproducing utricle. 



Distribution — New Zealand, Collins (4) ; Straits of Magellan, West 

 Patagonia, Svedelius (18); Sitka, Alaska, J. G. Agardh (1) and De A. 



