NO. 1 DAWSON : MARINE RED ALGAE OF PACIFIC MEXICO 31 



Kylinia crassipes (B<^rg.) Kylin 



Kylin, 1944, p. 13. Acrochaetium crassipes B<^rgesen, 1915, p. 20-22, 

 figs. 11-13; Taylor, 1928, p. 134, pi. 28, fig. 16. Rhodochorton micro- 

 scopicum (Niig.) Drew, as interpreted by Dawson, 1944, p. 254, pi. 41, 

 fig. 3. 



Thalli epiphytic, attached to the host by a single subglobose basal 

 cell giving rise to a single (rarely 2) uniseriate, arcuate axis which is 

 abundantly short-branched (1-3 cells), at first in a secund manner from 

 the convex side, later oppositely; fully developed plants often with op- 

 posite branches from every cell except the two basalmost and uppermost; 

 terminal cells commonly with a long hyaline hair ; reproduction by mono- 

 spores ; monosporangia mainly terminal on the short branchlets. 



Type: Holotype not designated. Syntypes of B<^rgesen's collection 

 are on slides in his private herbarium in the Botanical Museum, Copen- 

 hagen, Denmark. 



Type locality: Virgin Islands (four syntype localities men- 

 tioned ) . 



Mexican distribution: Pacific Baja Calif. — D. 9929a, on 

 Polysiphonia, 10 miles west of Punta Malarrimo, Apr. Gulf of Calif. — 

 D. 737-40, on Polysiphoniaj Isia Turner, Sonora, July. A large number 

 of young, unbranched plants probably of this species were found on 

 Gelidium decompositum at Isla Rasa (D. 1038a, Feb.). 



Reexamination of the plants reported by Dawson as Rhodochorton 

 micros CO picum indicate that the examples observed and illustrated were 

 immature. Further development of the plants causes them to produce 

 more branches, many of them opposite. They are frequently provided 

 with hairs as in the var. longiseta B^rg. The opposite branching is better 

 developed than in most of B^rgesen's material and agrees well with 

 Taylor's illustration. In the Mexican material the basal cell of mature 

 plants tends to be a trifle smaller than the cell just above. 



Kylinia arcuata (Drew) Kylin 



Kylin, 1944, p. 13. Rhodochorton arcuatum Drew, 1928, p. 165, pi. 

 37, figs. 1-3; Dawson, 1944, p. 255. 



Thalli epiphytic, attached by a single, subglobose basal cell somewhat 

 flattened on the attaching side ; erect filaments usually solitary from the 

 basal cell, but sometimes 2 or more, usually arising at an acute angle 

 from the host, or almost decumbent at times, to 100 /a long, 5.0-5.5 fi 

 in diameter, branched, the branchlets irregularly secund or sometimes 



