24 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



Mexican distribution: Pacific Baja Calif. — D. 9232A, in Hel- 

 minthocladia californica, Punta Pequena, Bahia San Juanico, May. 



Acrochaetium bonnemaisoniae (Batters) J. et G. Feldmann 



Feldmann, 1940, p. 458, Colaconema bonnemaisoniae Batters, 1896, 

 p. 8; Newton, 1931, p. 250, fig. 154. Chantransia bonnemaisoniae (Bat- 

 ters) Levring, 1937, p. 94, figs. 16a-c. 



Thalli endophytic in Bonnemaisonia; endophytic filaments flexuous, 

 much and irregularly branched, growing primarily in the plane of the 

 surface of the host, forming an irregular network between the cortical 

 cells ; cells irregularly shaped, simple, forked, cruciate or irregular, but 

 mostly elongated, somewhat angular and greater in diameter in the 

 middle than at the ends, 4-7 /x in greatest diameter, 10-25 [x long; chro- 

 matophore parietal ; monospores more or less spherical, 7-8 fi in diameter, 

 solitary or in groups of 2-3, mostly borne on short, 1-2 celled branches 

 extending to and beyond the surface of the host. 



Type : Holotype not designated, but the original syntype collections 

 by C. Brebner, Sept. 1895, and by E. A. Batters, probably are in the 

 British Museum, London. 



Type locality: In the cell walls of Bonnemaisonia asparagoides, 

 Plymouth, and Berwich-on-Tweed, England. 



Mexican distribution: Pacific Baja Calif. — D. 9667a, in the 

 cell walls of Bonnemaisonia hainifera, Punta San Quintin, Apr. 



Colaconema simplex Inagaki, 1935, p. 44 {Acrochaetium japonicum 



Papenfuss, 1945), also on Bonnemaisonia hajnifera, appears to difler in 



its always solitary monospores borne directly on the horizontal filament 



cells. 



I 



Acrochaetium eastwoodae (Setchell & Gardner) Papenfuss 



Papenfuss, 1945, p. 306. Rhodochorton eastwoodae Setchell & Gard- 

 ner, 1930, p. 166, pi. 4, fig. 8. 



Thalli epiphytic, 100-130 ju. high, attached to the host by a single cell 

 which gives rise to 1-3 (mostly 2) erect branches; erect branches sparsely 

 and alternately branched, usually dichotomous at the top of the first cell, 

 5-7 fju in diameter at the base, tapering very gradually to the apex and 

 terminating in a very slender hair; cells 2-4 times as long as broad, with 

 band-shaped chromatophores without pyrenoids ; basal cell 8.5-9.5 jx in 

 diameter; monosporangia sessile on the lower cells of the erect branches, 

 6-7 by 9-10 {x in dimensions; other forms of reproduction unknown. 



