28 bulletin: museum of comparative zoology. 



by nature, second growths, burned woodlands in various stages of 

 recovery, — • all are more or less important factors in the distribution 

 of bird-life. In addition to topographic features and to the usual 

 daily or seasonal movements which determine the presence of a species 

 in the lowlands, we must reckon with the occasional abnormally wet 

 or dry seasons, when certain species, perhaps never before or since 

 seen near the coast, suddenly appear in large numbers, even in the 

 more populous parts of the city. 



Thus while the present collection may be considered fairly repre- 

 sentative of the lowland avifauna of Surinam, many species are missing 

 which might have been obtained had the collector's efforts been 

 exerted over a larger area for a longer period. Also some which are 

 abundant at the coast, and not rare near Paramaribo, a few even 

 common in the city, are not represented; no doubt these could easily 

 have been included in the collection had a special effort been made to 

 obtain them. 



The arrangement of families is that used by Ridgway in the Birds 

 of North and Middle America, but beginning with the least specialized 

 forms. In the sequence of genera, species and subspecies, we have 

 followed Brabourne and Chubb in their Birds of South America. 

 Type-localities have been omitted whenever they are correctly stated 

 by Brabourne and Chubb. 



All measurements are in millimeters. Tail -measurements, unless 

 otherwise stated, are from the base of the free tail-feathers to the 

 extreme tip. 



In going over the collection, it was necessary to examine much 

 material from South and Central America, and the results are in- 

 cluded in the present paper. 



Summary. 

 List of species and subspecies described as new. 



Milvago chimacJiima cordata San Miguel Island, Bay of Panama. 



Rupornis magnirostris insidiatrix Santa Marta Mts., .Colombia. 



Herpetotheres cachinnans chapmani Quintana Roo, Mexico. 



Aramides cajanea latens San Miguel Island, Bay of Panama. 



Chaemepelia arthuri Vicinity of Paramaribo, Surinam. 



Puhatrix perspicillata trinitatis Island of Trinidad. 



Ceophloeus lineatus improcerus Bahia, Brazil. 



Chaetura brachyura jyraevelox Chateaubelair, St. Vincent. 



Lipaugus simplex frederici Vicinity of Paramaribo, Surinam. 



