188 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



Amphiroa annulata Lemoine 



Lemoine 1929, p. 78, pi. 4, fig. 1. 



Mexico: Is. Revilla Gigedo, on littoral rocks at Braithwaite Bay, I. 

 Soccoro, no. 34-27, 2 Jan. 1934. Costa Rica: stunted, in tide pools 

 near the entrance, Golfo Dulce, no. 39-116A, 26 Mar. 1939. 



Amphiroa peninsularis n. sp.^*'^ 

 Plate 48, Fig. 1 



Plants to 10 cm tall, rose pink, flexible, irregularly dichotomously 

 branched, erect, without much taper from base to apex; segments cylin- 

 drical or very slightly club shaped, occasionally bifurcate at the distal end, 

 0.8-1.2 mm diam. below, 0.5-0.8 mm in the terminal branches, in length 

 5-8 mm below, 4-7 mm above; smooth, or in the young segments with 

 annular markings, or below roughened with numerous slightly elevated 

 conceptacles about 0.4-0.5 mm diam. ; stiiictu rally, showing in the medulla 

 at intervals a zone of markedly small cells above which come four zones 

 of long cells which are successively slightly shorter from one small-celled 

 zone to the next above. 



This plant is very probably the A. nodulosa of Phyc. Bor.-Amer. no. 

 649 from False Bay, San Diego, California, collected by Mrs. E. Snyder, 

 Jan. 1899. The histological structure is the same, but the specimens are a 

 little larger. Kiitzing's type of A. nodulosa (1858, p. 19, pi. 41, fig. 1) 

 came from Venezuela; while his specimens (2.5 cm tall) might be the 

 upper parts of plants like ours, they show more taper and, if his drawing 

 of the medulla is correctly placed on the plate, the cell length sequence is 

 reversed. In the absence of comparative material it seems safest to describe 

 the western plant as new. The fragments which Lemoine (1929, p. 73, 

 pi. 3, fig. 7) describes as A. van Bosseae may be from a dwarf form of this 

 plant, but ours are hardly so coarse, so irregular or so obscurely segmented 

 as she describes for the Galapagos plant. 



Mexico: Baja California, on rocks about South Bay, I. Cerros, no. 

 34-646 A (TYPE), 10 Mar. 1934. Nayarit, common on large rocks 

 dredged from 24 meters' depth at sta. 970, I. Maria Magdalena, Las Tres 

 Marias, no. 39 -642 A, 9 May 1939. Guerrero, common in the littoral 

 on rocks in the surf, Ba. Petatlan, no. 34-568, 2 Mar. 1934. Ecuador: 

 Esmeraldas, dredged from 5.4 meters' depth off Ba. San Francisco, no. 

 34-483, n Feb. 1934. 



109 Amphiroa peninsularis n. sp. — Plantae ad 10 cm altitudine, dichotomae, 

 erectae, paululum teretes; segmentis paene cylindricis, diametro infra 0.8-1.2 mm, 

 ad cacumjna 0.5-O.S mm, longitudine infra 5-8 mm, supra 4-7 mm; segmentis 

 supra levibus aut paululum annulatis, infra per conceptacula subelevata asperatis, 

 0.4-0.5 mm diam. Planta typica in loco dicto South Bay, I. Cerros, Baja California, 

 Mexico, legit W. R. Taylor no. 34-646A, 10 Mar. 1934. 



