On the Life-History of Rhabdonia 
tenera, J. A g. 
BY 
WINTHROP J. V. OSTERHOUT. 
With Plates XX and XXI. 
HABDONIA TENERA , J. Ag., is a characteristic 
I V species of the warmer waters of the eastern coast of the 
United States, and is found abundantly in sheltered bays and 
coves. The abundance of the plant in certain localities near 
Woods Hole, Mass., together with the fact that certain peculiari- 
ties in the structure and development of the cystocarp and the 
proliferation of the tetrasporic plant seemed to be little under- 
stood, led the writer, while studying at the Marine Biological 
Laboratory at Woods Hole, to begin the investigation of the 
life-history of this plant with the hope of throwing some light 
upon these and other points. 
The species was first described by J. G. Agardh (’41) as 
Gigartina tenera, from specimens from the West Indies. Later 
(’51) he referred it to Harvey’s genus Rhabdonia . Harvey (’52) 
described it anew, and referred it to the European Solieria 
chordalis . J. G. Agardh (’71) subsequently stated that Harvey’s 
plant is his Rhabdonia tenera . Farlow (’75 and ’81) has given 
the best account of. the cystocarp. Schmitz (’89) separated 
the species from the genus Rhabdonia , and placed it in a new 
genus Agardhiella belonging to the Cystoclonieae. As the 
description of the new genus has not yet appeared, I have 
preferred to retain the older name. 
[Annals of Botany, Vol. X. No. XXXIX. September, 1896.] 
