702 University of California Publications in Botany [Vol.8 



Pelvetia fastigiata f, gracilis S. and Gr. 



Plate 78a 



Plants profusely and dichotomously branched, central branches 

 becoming much longer than those on the outside of the mass, giving 

 to the whole plant a more or less spherical outline ; frequently branches 

 arise from near the base and develop a mass of short branchlets ; 

 fronds slender, the terminal branchlets 1-3 mm. diam. ; fruiting in 

 the summer and autumn. 



Growing in the middle of the littoral belt. Carmel Bay, Pacific 

 Grove, and Santa Catalina Island, California. 



Setchell and Gardner, in Gardner, New Pac. Coast mar. alg., I, 

 1917, p. 386. 



In the above mentioned localities, plants grow in groups, quite 

 separate from the typical P. fastigiata. The plants as a whole are to 

 be distinguished chiefly by their very slender fronds throughout as 

 compared with the typical form. 



67. Pelvetiopsis Gardner 



Fronds arising from a disk-shaped holdfast, frequently the hold- 

 fasts confluent, cylindrical at the base soon becoming flattened and 

 more or less concave-convex and contorted, ecostate, receptacles con- 

 spicuous, terminal, almost cylindrical and acuminate or flattened and 

 blunt ; oogonium producing but one viable gamete, or egg, the other 

 seven nuclei extruded in a single, small, non-viable sphere cut off from 

 the lower part of the oosphere ; cryptostomata sparse on the young 

 plants ; hermaphroditic. 



Gardner, Nuclear Extrusion, 1910, p. 127, New Fucaceae, 1913, 

 p. 320. 



This genus is well marked both macroscopically and microscopically. 

 It is more closely related to the genus Pelvetia than to the genus Fucus 

 in its gross morphological characters, but differs from both in the 

 production of but a single viable gamete in the oogonium. In this 

 latter respect it is like the genus Hesperophycus, but differs decidedly 

 from that genus in its gross morphological characters. 



