350 



SCIENCE 



[N. S. Vol. XXXII. No. 819 



cella vulgaris and Centropyxis aculeata, 

 shell-bearing rliizopods, were most abundant. 

 These are among the more common species in 

 the United States. Only one species with 

 ray-like pseudopodia was observed, a member 

 of the genus Baphydiophrys, probably a new 

 form. 



The scarcity of Mastigophora was especially 

 marked. In material where certain common 

 forms are usually found in swarms there were 

 none. The Euglenidse were few in species 

 and in number of individuals. Only one form 

 of flagellate was at all common, Ohilomonas 

 Paramecium, which may be found almost 

 everywhere in stagnant water. 



The class Infusoria was well represented 

 except in a few particular groups. 



The Vorticellidae, common forms with us, 

 were represented in the collections by only 

 four species, rarely seen and only one of 

 which could be identified as a North Ameri- 

 can species. None of the beautiful colonial 

 examples of Epistylis or Carchesium were 

 found. 



Stentor was not discovered, even in the old 

 infusions, after fermentation had taken place. 



No members of the subclass Suctoria were 

 obtained. This failure, however, does not in- 

 dicate that none existed, as these forms are 

 by no means abundant in any locality. 



The list as reported is not a large one, but 

 nevertheless is a representative one, compris- 

 ing 21 families and 34 genera. 



In June, 1908, the writer did enough work 

 on the protozoa of southern California to con- 

 clude that the one-celled animals of that re- 

 gion are identical with those of the central 

 portion of the United States, and the species 

 here are, for the most part, reported from 

 eastern United States by Stokes, Conn, 

 Palmer and others. 



A species of Colpoda, common in this state, 

 was, during the summer of 1906, the predomi- 

 nating species in infusions of the leaves of 

 the shrub on Loggerhead Key, Dry Tortugas. 



It is well known that environment may 

 have a direct morphological and physiological 

 influence upon the protoplasm of the unicel- 

 lular animal, and, no doubt, external factors 



are instrumental in the production of the 

 numerous variations of certain protozoa, yet 

 the significant fact is that there is a constancy 

 of species and that a given species may flour- 

 ish under very diverse habitat conditions. 



All of the evidence indicates that very 

 many species of protozoa are widely distrib- 

 uted throughout the United States and many 

 of these same species are common forms in 

 oceanic islands separated from our shores by 

 several thousands of miles of sea. 



It is safe to conclude, I believe, that on 

 every land surface of the earth, -where mois- 

 ture abounds, within wide range of latitude 

 and altitude, we may expect to find, not only 

 genera, but species of protozoa identical with 

 those of this immediate vicinity. 



Appended is a list of the species of protozoa 

 reported from Tahiti. 

 Sarcodlna : 



Amwba proteus 



Amoeba radiosa 



Dinamoeba sp. 



Difflugia pyriformis 



Ar cella vulgaris 



Arcella discoides 



Centropyxis aoyleata 



Cochliopodium bilimbosum 



Euglypha alveolata 



Trinema enchelys 



Raphidiophrys sp. 

 Mastigophora : 



Euglena vvridis 



Euglena acus 



Astasia triohophora 



Entosiphon sulcatus 



'Notosolenus opocamptus 



Chilomonas Paramecium 

 Infusoria: 



Coleps hvrtus 



Prorodon edentatus 



Mesodinium, sp. 



Laorymaria truncata 



Lioivotus fasciola 



Loxodes rostrum 



Chilodon cucuUulus 



Loxocephalus granulosum 



TJrocentrum tubro 



Microthorax sulcatus 



Cinetochilum margaritaceum 



Paramecium caudatum 



Paramecium trichium 



