94 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 26 



Nr. 31387 "California, Farlow," Nr. 31388 "Santa Barbara [California] 

 L. N. Dimmick" (illustrated by Kylin.) 



Mexican distribution: Pacific Baja Calif. — D. 13389, 14 m ^ 

 off Punta Entrada, Isla Magdalena, 26 m. 



Acrosorium uncinatum (Turner) Kylin 

 PI. 43, fig. 2 

 Kylin 1924, p. 78; Taylor 1945, p. 285; Dawson 1945d, p. 63, 67; Dawson, 

 Neushul & Wildman 1960, p. 38, pi. 34, fig. 1. Fucus laceratus var. uncinatus 

 Turner 1808, p. 153, pi. 68, fig. c-d. 



Thalli usually epiphytic or entangled, or attached to pebbles or shell 

 fragments by rhizoids, rose red, 2-5 cm. tall, bushy when amply devel- 

 oped, consisting of irregularly branched ligulate, membranous blades 

 1-2 mm. wide with entire margins; blades with subacute tips and usually 

 with strongly hamate branchlets, with a system of microscopic nerves in 

 the otherwise monostromatic blade; reproduction by fragmentation and 

 reattachment, or, in the Pacific Coast plants, exceedingly rarely by 

 tetrasporangia (observed only once among many hundreds of speci- 

 mens) . 



Type: A collection by "Miss Hill' probably to be found among the 

 Dawson Turner materials in the Herbarium at Kew or in the British 

 Museum. 



Type locality: Tenby, England. 



Mexican distribution: Pacific Baja Calif. — D. 7909 (Hubbs) 

 Tijuana Slough; D. 7950 (Hubbs) Islas Coronados; D. 8041 (Hubbs) 

 Bahia Descanso; D. 19214 (Norris) Punta Banda; D. 8253, 8271 (45- 

 55 m.), 8278, 8488 (75-100 m.), 8444 (95 m.), 19233 (Limbaugh & 

 Chester 20-25 m.), 19291 (Hubbs) Isla Guadalupe; D. 20449 (Neushul, 

 18 m.), D. 6558 (38 m.) Isla Cedros; D. 7891 (Osorio-Tafall) Isla 

 Natividad; D. 20287 (Neushul, 20-25 m.) Islas San Benito; D. 20476 

 (Neushul, 35 m.), 20495 (Neushul, 10-15 m.) southern Bahia Viscaino; 

 D. 20842 (Neushul) Punta Eugenio; D. 20576 (Neushul) Bahia Tor- 

 tuga, 11-15 m.; D. 20378, 20420, 20428a (Neushul, 10-12 m.) Isla 

 Asuncion; D. 13249, Punta Pequena; D. 20344 (Neushul, 8 m.), D. 

 20358 (Neushul, 20 m.), D. 7904, Bahia San Hipolito; D. 7277, 7249, 

 (3 m.), Taylor 34-605, Bahia Santa Maria; D. 20202 (Neushul 15 m.), 

 D. 6607, 6608 (25 m.), D. 13386 (26 m.) Punta Entrada, Isla Magda- 

 lena; D. 6723 (35 m.) Isla Margarita; D. 13342, Punta Lobos; D. 6876 

 (38 m.) Bahia San Lucas. 



Key to the Mexican Species of Myriogramme 



1. Thalli 10-20 cm. tall M. spectabilis 



1. Thalli 3 cm. tall or less 2 



2. Plants with densely congested, ruffled blades joined together 



by accessory attachment discs M. caespitosa 



2. Plants not as above, the blades essentially free 3 



