1920] Setchell-Gardner : Chlorophyceae 203 



4. Chaetomorpha antennina (Bory) Kuetz. 



Filaments dark green, tufted, 4-9 cm. long, erect, rigid below, 

 somewhat less so above, more or less clavate ; basal segments 5-9 mm, 

 long, emitting long, slender, intertwined, branching rhizoids from its 

 base; segments 450-900jU, in diameter, 1^ times as long as broad, 

 fertile somewhat swollen, walls finally thickened (up to 25,/x thick) 

 and stratified. 



St. Augustin and Mazatlan, Mexico. 



Kuetzing, Sp. Alg., 1849, p. 379; Collins, Green Alg. N. A., 1909, 

 p. 324, Suppl. II, 1918, p. 79; Howe, Mar. Alg. Peru, 1914, p. 37. 

 Conferva mitemnina Bory, Voy. quatre iles d'Afr., vol. 2, 1804, p. 161, 

 Voy. Coquille, 1828, p. 227 ; Montague, Voy. au Pol Sud, 1845, p. 4. 

 Chaetomorpha pacifica Kuetzing, Sp. Alg., 1849, p. 379. 



There are two coarse, rigid species of Chaetomorpha on the Pacific 

 Coast of North America, viz., C. melagonimn and C. antennina. The 

 first is Alaskan, inhabiting the cold waters of the Boreal zones, while 

 the second is found in tropical waters on the coast of Mexico. C. mela- 

 gonium is a species reaching a length of several dm. while C. antennina 

 is seldom over 1 dm. The basal segment in C. nielagonium is short, 

 not over 3 mm., while that of C. antennina is long, reaching a length 

 of 5 to 9 mm, 



Howe (loc. cit.) has examined the type of Chaetomorpha antennina 

 (Bory) Kuetz. and also the Mexican type of C. pacifica Kuetz. He 

 judges them to belong to the same species as does also the Chaeto- 

 morphopsis pacifica Lj^on {in Tilden, Amer. Alg., Cent., 5, 1901, no. 

 458). He has also examined the Mazatlan plants collected by Dr. and 

 Mrs. Marchant and, although there are some differences in diameters 

 and length of basal segments, expresses his opinion that they, also, are 

 best placed under C. antcAinina. 



The type locality of Chaetomorpha antennina is Reunion or Bour- 

 bon Island. The specimens upon which C. pacifica is based come from 

 Java and from St. Augustin, Mexico. Lyon's Chaetomorphopsis 

 pacifica came from the Hawaiian Islands. Chaetomorpha antennina, 

 then, in this interpretation is a widespread Indo-Pacific species, rang- 

 ing from the tropical shores of Pacific North America to those of 

 eastern Africa. The West Indian specimens formerly referred to 

 C. antennina seem better referred to C. media (Ag.) Kuetz. (cf. Howe, 

 1914, p, 37). 



