ROTATOKIA OF LOS ANGELES, CALIFORNIA, AND VICIN- 

 ITY, WITH DESCRIPTIONS OF A NEW SPECIES. 



By Frank J. Myers, 



Of Bethlehem, Pennsylvania. 



INTRODUCTION. 



The collections upon which this report is based were made by the 

 writer from January to May, 1916. While the number of species 

 listed is not large, the record is interesting in view of the fact that 

 nothing is known of the Rotatoria of California; it is hoped that 

 local students may take up the subject and extend the list. 



Los Angeles is situated on a narrow, level plain intervening be- 

 tween the foot of the San Gabriel Mountains and the Pacific Ocean. 

 The Los Angeles River, which passes through the city, has the usual 

 characteristics of mountain streams ; at times it is torrential and at 

 other times its bed is practically dry. 



On account of the narrowness of the level plain no large lakes exist, 

 and as there are but two seasons, a rainy and a diy one, permanent 

 pools and ponds are not numerous. The majority of the collections 

 are consequently from artificial reservoirs and ornamental pools in 

 and around the city. Through the kindness of Mr. WiUi MulhoUand 

 I obtained access to the various storage reservoirs from which the 

 water supply of the city is obtained. 



Ml'. H. K. Harring, of the United States National Museum, has 

 cooperated in the determination of some of the species and added a 

 note on Pleurotrocha daphnicola. 



For convenience the different localities at which collections were 

 made are referred to by numbers, as foUows: 



1. Permanent pool, about 1 acre in area, formed by surface drain- 

 age and overflow from a small artificial lake in East Lake Park, 

 Los Angeles. 



2. Slowly running water in BaUona Creek, a very small stream 

 about 4 miles west of Los Angeles. 



3. From service pipe of the city water supply. 



4. Nigger Slough, a large body of water about 11 miles south of 

 Los Angeles, supplied by surface drainage and melted snow from the 

 San Gabriel Mountains. 



Proceedings U. S. National Museum, Vol. 52-No. 2190. 



473 



