NEW MYXOPHYCEAE FROM PORTO RICO 



Nathaniel Lyon Gardner 

 (with plates 1-23) 

 Introduction 



The new species of ALyxopliyceae proposed in tliis paper are 

 based almost wholly upon material collected by Dr. N. Wille on 

 the Island of Porto Rico during a three months' collecting trij) 

 extending from December 23, 1914, to March 24, 1915. The enter- 

 prise was undertaken by Dr. Wille upon the invitation of Dr. N. 

 L. Britton and carried through under Dr. Britton's direction in 

 the interest of The New York Botanical Garden. The account 

 contains no marine species, since Dr. Wille 's commission was to 

 collect only fresh-water forms. This he seems to have done with 

 unusual thoroughness, having assembled in his comparatively 

 brief sojourn over two thousand specimens, furnishing each with 

 data as to .time, habitat, and locality. The collections included 

 Chloroj^hyceae and Myxophyceae, with a few simple Hhodo- 

 phyceae, assembled from almost every conceivable habitat. 

 Stone bridges, old fences, and the walls of various old forts and 

 buildings were found to be favorite habitats. Pools, ponds, quiet 

 and swiftly running streams, and numerous hot springs fur- 

 nished abundance of both Chlorophyceae and Myxophyceae. 

 Terrestrial sj^ecies occur frequently in the list. Arboreal forms 

 seem to abound everywhere. Interesting mixtures were fre- 

 quently taken from rock ledges, especially of limestone. There 

 seems scarcely to have been a habitat which Dr. Wille over- 

 looked and which did not yield a profitable supply of some one 

 or more forms. Species of both the Green and the Blue-Green 

 groups occur abundantly as the gonidia of very small and simj^le 

 lichens. 



One of the i^rominent features of the algal flora of the island 

 is the interminable mixtures in which the)" abound. Scarcely a 

 single collection which came to my notice consists of a pure 

 single species. The multiplicity of intermingled forms made 

 their determination oftentimes very difficult, especially so 



