162 i\Ir. ('. B. Williams' Notes on 



tells ]ue that about 1906 he saw a migration of some 

 thousands of yellow butterflies crossinfi the Demerara 

 River from Plantation Diamond to Plantation Wales, 

 that is, from the east to the west bank about six miles from 

 the mouth of the river. They were flying with a strong 

 wind behind them. 



12. The Rev. Mr. Salmon tells me that at Wismar (about 

 sixty miles up the Demerara River) at the beginning of 

 August 1916 he saw a " procession " of yellow butterflies 

 between his house and the river. They were flying .in 

 groups of ten to twenty, with a short interval between 

 each group. The flight was first noticed at mid-day and 

 lasted for several hours after this. It might have already 

 been proceeding for some time. They were flying approxi- 

 mately from N.N.W. to S.S.E. 



13. Messrs. Bancroft and Ward described to me a migra- 

 tion that they had seen a few days before, about the 20tli 

 September, 1916, at Murirato, about ten miles above 

 Wismar on the Demerara River. The butterflies were all 

 flying from the left to the right bank of the river, that is, 

 from west to east. 



14. Richard Schomburgk, in " Reisen in Britisch Guiana," 

 Zweite Theil, Leipzig, 1848, p. 157, describes a migration 

 of yellow butterflies which flew from S.E. to N.W. in the 

 interior of British Guiana near Pirara about the 13th 

 September, 1842. The flight lasted the whole day, and at 

 mid-day and just before sunset the butterflies settled in 

 countless numbers on the patches of sand at the edge of 

 the river. According to the natives they were the butter- 

 flies which came from certain caterpillars and chrysalides 

 which they readily ate. 



15. Both Moore (/. c.) and Rodway (" In the Guiana 

 Forest," 2nd edition, p. 122) refer to a record of a migration 

 by Robert (not Richard) Schomburgk. of which, however, 

 I have been unable to trace the original. Moore says it was 

 observed by Sir Robert Schomburgk " on the 18th of 

 October, 1838, when going up the Essequebo, and it con- 

 tinued crossing the course of the river for nine hours and 

 a half, during which time his boat ascended nine miles, 

 A thousand million is not too high an estimate for the 

 number of individuals in the swarm." 



16. This last record relates not to Callidryas euhule, but 

 to another Pierid, Ajypias margarita, a small white species. 

 Mr. A. Leechman, in the " British Guiana Handbook," 



