160 Mr. C. B. Williams' Notes on 



tion at Bartica at the junction of the Essequebo, Cuyiini 

 and Mazaruni Rivers, and from there down towards the 

 mouth of the Essequebo. On the 11th September I 

 noticed that all the Callidryas passing over the garden of 

 the house where I was staying (at H. M. Penal Settlement 

 on the opposite bank of the Mazaruni to Bartica) were 

 flying in the same direction, towards the N.N.W., at full 

 speed. They were not common, and in twenty minutes 

 (12.40-1 p.m.) I only counted thirty-nine, i. e. about two 

 a minute; during that time not a single one was seen to 

 settle, or fly in any other direction. They were still 

 passing over about half an hour later, but after that the 

 usual afternoon rains came on and they were not seen 

 again that day. There was a slight east wind blowing at 

 the time. On the following day (12th September) at 

 Bartica, several were seen, again all flying full speed N.N.W. 

 On the 13th September I descended the Essequebo to the 

 mouth by steamer, and during the early part of the journey 

 Callidryas were flying N'.N.W. at the rate of four or five a 

 minute on a two hundred yards line. There was then 

 practically no wind. About 10.30 a.m. the north-east trade 

 wind became stronger, and the flight changed to a westerly 

 direction (almost directly across the river instead of down 

 it). This would be the natural resultant of a N.E. breeze 

 on an attempted flight in a N. or N.N.W. direction. 



4. Mr. Withers, Manager of Hills Estate, Bartica, w^ho 

 has resided in the district about seven years, tells me that 

 he has many times seen the yellow butterfly migrating, 

 sometimes for days together, ahvays in a N. to N.W. 

 direction. These flights, he says, usually occur in October, 



5. Mr. Frear, Chief of H. M. Penal Settlement, tells me 

 that about the beginning of August 1916 there w^as a small 

 flight about ten miles up the Mazaruni River flying north- 

 west. This would be about the same time as I saw them 

 at Issororo, flying in an exactly opposite direction. 



6. Mr. Cameron, Acting Chief Engineer of the Govern- 

 ment Steamer Service, tells me that on the 8th September, 

 1916, he saw a small number of yellow butterflies at 

 Camaria on the River Cuyuni, about eight miles above the 

 Penal Settlement, all flying north-west. 



7. H. W. B. Moore, in " Timehri," the Journal of tlie 

 Royal Agricultural and Commercial Society of British 

 Guiana, 3rd Series, vol. ii (1912), p. 405, says: "In 

 Julv ... I observed thousands of Callidryas eubule . . . 



