202 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



According to de Toni (1897), it is identical with Ulva ati'o- 

 ptcrpurea Olivi.^ 



Habitat. — On rocks and epiphytic on algse ( Gracilai'ia 

 confervoides); lower litoral and sublitoral zones; March 

 to May. 



Distribution. — The author is aware of but a single region 

 of the Pacific Coast where this species occurs; i. e., Mon- 

 terey Bay, California (36^ 45' N. lat.). 



Localities. — Pacific Grove, California (M. A. Howe!, 

 Mrs. J. M. Weeks!, W. A. Setchell No. 5161!); Santa 

 Cruz, California (Mrs. J. M. Weeks!, de A. Saunders!). 



4. Porphyra perforata J. Ag. 



Plate XX, Figs. 4^-10. 



Till Alg. Syst. Afd. 3, VI, 1882, Ulvacese, p. 69. 



Porphyra perforata J. Agardh, Till Alg. Syst., Afd. 3, VI, 1882, Ulvacese, 

 p. 69. Hus, in Phyc. Bor.-Amer., Fascl. XIV, Collins, Holden & 



Setchell, No. 682, 1900. Hus, Zoe, Vol. V, 1900, p. 63, 

 Porphyra w^/^arw Anderson, Zoe, Vol. II, 1891, p. 221. Howe, Erythea, 



Vol. I, 1893, p. 67. 

 Wildema7tia perforata de Toni, Syll. Alg., Vol. IV, 1897, p. 21. 



Membranous, 7-70 cm. long, 3-20 cm. broad; linear-lanceolate, with undu- 

 late margin, often much expanded and laciniate; base cordate to umbilicate; 

 attached by a disc; gray to brown-purple, becoming blue-purple on drying; 

 monostromatic, vegetative part of frond 45-140// thick; cells once to two and 

 a half times as high as broad; surface jelly thick, often forming two-fifths of 

 the thickness of the frond; monrecious, sporocarps and antheridia in irregular 

 patches, the latter radiating towards the margin; vegetative cells often mixed 

 in with the sporocarps, never with the antheridia; each sporocarp containing 

 32 carpospores, each antheridium containing 128 antherozoids. 



This species is known to the author from specimens col- 

 lected by Mrs. Snyder at San Diego, some of which were 

 communicated to the late Professor J. G. Agardh, and 

 referred by him to P. -perforata. 



It is an annual, found throughout the year, the young 

 fronds making their appearance before the old ones have 

 altogether disappeared. Where the fronds are exposed to 



1 Saggi Accad. di Padova III, i, (prses. die i8 Martii 1791), p .153, Tab. I-III (fide de 

 Toni). 



