150 Mr. C. B. Williams' Records of 



This migration is of particular interest, for two reasons. 

 In tl'e first place, it is the first authentic record I have 

 obtai ed of a migration during the dry season. There is 

 one record in my previous paper (1919, p. 88) in which 

 the butterflies were said to be " looking for water," but 

 the dat ^ of this was uncertain. 



In u^xO present case the migration was preceded by six 

 weeks of extremely dry weather, as m 1919 the dry season 

 in Trinidad started at the very beginning of January. 



The second point of* great interest is that the direction 

 of the flight was not the same throughout its range, but 

 consisted of a fan-shaped spread from some area near the 

 middle of the south coast, as will be seen distinctly from 

 the directions of the arrows on the accompanying map 

 (Fig. 1). 



1919. March. 



On 15tli March, after two and a half months of extremely 

 dry weather, heavy showers fell over the greater part of 

 the island and continued during the following two days. 



On the 17th March, at about 12.30 p.m., yellow butter- 

 flies were passing along the east side of San Fernando hill 

 in a northerly direction in sufficiently striking numbers 

 to warrant my being informed by telephone of the event. 



On the west side of the hill, where my house is situated, 

 they were then seen to be passing in a very thin but steady 

 flight of three or four per minute, but the movement did 

 not last much longer, and was over by 1 p.m. 



1919. Dry Season. 



Mr. Cecil Rostant, a resident of Moruga (south coast), 

 tells me that " some time about the middle of the dry 

 season " the butterflies passed over Moruga in large num- 

 bers. They flew to the west during the morning, but in 

 the afternoon turned northward. 



It is impossible to say if this record refers to the February 

 migration or not. 



1919. July. 

 Mr. J. A. Bulbrook, a geologist who had been in camp 

 at Palo Seco (south coast) for some months, informed me 

 on 29th July, 1919, that since 11th July the butterflies had 

 been passing irregularly from north-west to south-east. 

 He considers the movement not distinct ])ut quite certain. 



