3o6 CALIFORNIA ACADEMY OP SCIENCES. [Proc. 3D Ser. 



as were Forster's Tern on the 23rd of September, the 

 Black-bellied Plover on the 24th, and the Pomarine Jaeger 

 on the 25th. 



2. With the advance of the season the flights gained in 

 strength, as in the Loons and Surf Scoters. 



3. Sardines were passed over or slightly regarded on 

 several occasions (particularly October 21, 31), seemingly 

 manifesting that the Shearwaters were bent on a journey, 

 and not merely seeking food, feeding, or resting, as on 

 October 15, 23, 26, 28, 30, 31. 



4. All the northward flights were insignificant compared 

 with the southward ones, and were not more pronounced 

 than the retrograde movements of the Dark-bodied Shear- 

 water and the northern species during the temporary halts 

 in migration.^ 



5. At the close of December, 1894, and in January, 

 1895, the sexual organs of specimens taken were much 

 enlarged,^ evincing that the breeding season was approach- 

 ing. No such functional activity was detected in the 

 autumn of 1896, although numerous individuals were 

 dissected. 



6. These Shearwaters were absent from the vicinity of 

 Monterey through May and early June, 1897, and June, 

 1894^ — for a longer time than the interval between the end- 

 ing of the northward and the beginning of the southward 

 migration in the Northern Phalarope.'' 



It seems highly probable therefore that the autumn and 

 winter Black-vented Shearwaters off Monterey were migrat- 

 ing to breeding grounds lying to the southward, probably 

 not above the subtropics, the northern boundary of the 

 breeding range apparently corresponding in latitude to that 



1 There are eddies ifi migration as in the Mississippi, where a current sets in the 

 opposite direction from the main flow of the stream. This was especially exemplified 

 in the closing of the northward migration in 1897, when counter-currents of Northern 

 Phalaropes set strongly southward. 



2 Calif. W. B. No. II, pp. 3, 5. 



3 Ibid., No. I, pp. 205, 216. 



* Ibid., p. 187; forthcoming No. V. 



