184 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



Panama : scarce, on Jania in lower tide pools, Bahia Honda, no. 39- 

 133 (p.p.), 26 Mar. 1939. Ecuador: Guayas, epiphytic on Jania, lit- 

 toral of the southeast side of Pta. Santa Elena, Salinas, no. 34-472A p.p. 

 (TYPE), 8 Feb. 1934. 



CHOREONEMA Schmitz, 1889 



Plants minute, lightly calcified, of sparse endophytic parasitic mono- 

 siphonous branched filaments; pericarps rounded subconical, sessile, the 

 wall of relatively large cells, with an apical pore. 



Ghoreonema Thureti (Bornet), Schmitz,/. 

 Plate 45 



Bornet in Thuret 1878, p. 96, pi. 50, figs. 1-8 (as Melobesia Thureti) ; 

 Schmitz 1889, p. 455; Suneson 1937, p. 53, figs. 33-35, pi. 3, figs. 10-12. 



These very interesting little plants were found on a few tufts of Jania 

 ungulata, and in aspect agree excellently with the figures in Thuret's 

 Etudes Phycologiques. The walls of the pericarps seem translucent and 

 little calcified. No study of the reproductive structures was made. Bornet 

 (loc. cit.J does not give measurements for the pericarps, but from the 

 scale of his illustrations one may assume that the pericarps are a trifle 

 shorter than broad as a rule, and about 92-128 /x tall, 80-128 /* wide. 

 The present Galapagos material, using only the larger pericarps, gave 

 measurements of 77-91 ^ tall, 84-98 fx w^ide; these measurements, while 

 less than those of the type material, overlap them, and one hesitates to 

 describe these plants as a new species under such circumstances. 



Ecuador : Archipielago de Colon, endophytic in Jania, intertidal on 

 a reef north of Tagus Cove, I. Isabela, no. 34-1 69B, 13 Jan. 1934. 

 Salinas, on Jania dredged along the village beach in 2-4 meters' depth, 

 Schmitt no. 12D-33 p.p., 19 Jan. 1933. 



LITHOTHRIX J. E. Gray, 1867 



Lithothrix Aspergillum J. E. Gray 



Fragments showing a main axis of slightly compressed segments about 

 0.5 mm diam., and about as long, each segment bearing simple subopposite 

 patent to erect branchlets of 0.2-0.25 mm diam., with segments a little 

 longer or shorter than broad, slightly cask shaped, 2-3 mm long, and an 

 occasional branchlet not in the plane or the frond ; conceptacles generally 



