264 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



under side and erect branches on the upper; creeping filaments 32 /x to 

 more generally 42-57 fj. diam., the cells cylindrical to slightly swollen; 

 haptera commonly on several adjacent cells, when present generally borne 

 near the posterior end, unicellular, simple or rarely to 360 /a long or even 

 longer, the end occasionally acute, generally expanded sharply into a 

 lobed disk; erect filaments simple or very sparingly alternately branched, 

 36-72 /i diam., the cells cylindrical or veiy slightly swollen, 60-180 n 

 long or generally 2-3 diameters, rather more slender and with propor- 

 tionately shorter cells near the tips, which are 25-40 p. diam. and slightly 

 tapered to the rather obtusely rounded end cell ; sporangia nearly spherical, 

 tetrahedral, 54-70 ix diam., about 4-6 in unilateral series, or occasionally 

 opposite, near the middle portion of the fertile axis, the first produced on 

 1-2-celIed upcurved stalks formed at the upper end of the cells, the stalks 

 frequently branching from below, and rebranching, the sterile apices arch- 

 ing part way around the older sporangia until they develop into secondary 

 sporangia in turn; dioecious, the spermatangia in unilateral series of 6-10 

 clusters near the upper end of the fertile axis, each cluster sessile near the 

 top of the supporting cell, oval cylindric, about 40-45 ix diam., 72-90 /x 

 long; cystocarpic plants with more spreading branches than the other 

 types, the cystocarps produced singly at the tip of the main axis and often 

 on one or two lateral branches, commonly subtended by single or opposite 

 spreading elongated sterile branches from the cell below, about 180 /* 

 diam., the sterile central portion obvious, the carposporangia terminal on 

 the gonimoblasts, about 30 fi diam. 



This plant seems amply distinct from the rock-growing S. Snyderae 

 Farlow, which is much taller and more branched, has much larger cells, 

 and forms fewer sporangia. It is a good deal coarser than S. Gorgoneum 

 (Montagne) Bornet (Taylor 1942, p. 121, pi. 4, figs. 1-4) and shorter 

 celled than S. macromeres Collins & Hervey (1917, p. 132), which are 

 the chief Atlantic tropical American species. It is of about the same size 

 as the epiphytic S. flabellatum Bornet (Feldmann-Mazoyer 1940, p. 360, 

 fig. 137) of the Mediterranean, but branches more sparingly, tapers less, 

 and has shorter cells. 



Ecuador : Archipielago de Colon, abundant on Galaxaura from surf- 

 beaten rocks south of Black Beach Anchorage, I. Santa Maria, no. 34- 

 397 (tetrasporic, spermatangial, cystocarpic, TYPE), 30 Jan. 1934. 



