— 148 — 



Found in shallow water in sheltered places, e. g. in lagoons 

 where it was growing upon the roots of the mangroves. 



St. Croix. Ghristiansteds Lagoon, Long Reef. St. Jan. 

 Crux Bay. 



var. Leprieurii Kütz. 



Bryopsis Leprieurii Kütz., Spec, algarum, 1849, p. 490, Vickers, Phyco- 

 logia Barbadensis, pi. 50. 



Of this variety some rather typical specimens were found but 

 others were more or less intermediate between the above-mentioned 

 varieties. 



Occurred in rather sheltered localities in shallow water. 

 St. Croix. Christiansteds Harbour; St. Thomas, The Har- 

 bour (Hurricane Hole); St. Jan, Cruz Bay. 



Yaucheria dichotoma (L.) Ag. 



G. Agardh, Synopsis Alg. Scand., 1817, p. 47. 



In the dimensions of the thallus the form found seems to agree 

 very well with f. marina Hauck "Meeresalgen", p. 412. 



Lat. thallus = 90— 150 ^t. 



— oospor. = ca. 270 p.. 



— antherid. = ca. 100 ß. 

 Long. — = ca. 175//.. 



It was found on soft, moist bottom at the shores near Krauses 

 Lagoon, St. Croix. 



In "Algologiska småsaker" (Bot. Notiser 1869) Nordstedt 

 mentions that he had found a specimen of this species from St. 

 Thomas in Herb. J. Agardh: "hab. in lignis fluitantibus. Ser. E 

 n:o 36 (Duchassing)". 



During a visit to Paris (Oct. 1908) I was able through the courtesy 

 of M. Paul Hariot to examine a specimen of Mazé and Schramm's 

 Algues de la Guadeloupe determined as Chlorodesmis comosa 

 and it seemed to me rather probable that this plant was the male 

 plant of Vaucheria dichotoma. As now this specimen bears a great 

 likeness to the sterile one I referred with much doubt to Avr. 

 comosa in an earlier paper x ), I think it is rather probable that my 

 specimen belongs to this species. 



x ) Børgesen, F., The species of Avrainvilleas hitherto found on the shores 

 of the Danish West Indies (Vidensk. Meddel, fra den naturh. Foren, i Kbhvn. 

 June 1908). 



