604 



SCIENCE 



[N. S. Vol. XL. No. 1034 



and Portoviejo and returning to Guayaquil 

 by way of Manta. Several more weeks were 

 spent in tlie rivers Daule and Vinces. He then 

 ascended into the high Andean plateau over 

 the Guayaquil and Quito Railway, collecting 

 at various points. Prom Quito he descended 

 again into the subtropical forest region at 

 Mindo on the western slopes of Mt. Pichincha. 

 The expedition then continued northward to 

 El Angel, where several weeks were employed 

 excavating old Inca tombs. Nearly 300 pieces 

 of Inca pottery were obtained; these are now 

 in the John Herron Art Institute of Indian- 

 apolis and the Carnegie Museum. Mr. Henn 

 went from here down the valley of the Ghota 

 to a point below the hacienda Paramba. 



Revolutionary developments and the pres- 

 ence of roving bands of " montoneros " made 

 necessary a return to Quito, where the month 

 of January was spent. Here a small collection 

 of birds, aggregating about 65 species, was ob- 

 tained, chiefly from Pichincha and the sur- 

 rounding region. When quiet again pre- 

 vailed, Mr. Henn returned to El Angel to 

 secure the stored collections, continued on 

 through Tulcan to the Colombian frontier and 

 thence to Barbacoas, reached after twelve days 

 of continuous travel by mule from Quito. He 

 arrived in New York at the end of March of 

 this year after fifteen months in the field. 

 Aside from the collections of fishes, the col- 

 lection of batraohians comprises probably 400 

 specimens, representing all ranges of altitude 

 and climate. The collection of mammals is 

 insignificant, of note is the acquisition of four 

 skulls and one skin of the rare spectacled bear 

 (Tremarctos ornatus). This expedition was 

 made possible by the generosity of Mr. Hugh 

 McK. Landon, of Indianapolis. 



The general result of these expeditions if 

 the definition of two geographical sub-prov- 

 inces, of more or less equal value, differing 

 somewhat in their constitution, but more so 

 in their origin. The Pacific Province of con- 

 tinental South America may be divided into 

 two sub-provinces, (1) the Colombian, ex- 

 tending from the Chepo basin of Panama 

 south to the river of Esmeraldas and (2) the 

 Ecuadorian, extending from the Guayas system 



south until lost, probably in the desert of Ata- 

 cames. The fishes of the Pacific slope are in 

 general widely distributed Amazonian tjrpes; 

 none of them would cause surprise if taken at 



The Colombian sub-province is character- 

 ized by its extreme humidity. None of its 

 rivers are large, the San Juan and Patia are 

 the largest, but all carry a relatively immense 

 amount of water. The few fishes which have 

 come into them have undergone much adaptive 

 radiation. Its fauna is much richer than that 

 of the Ecuadorian sub-province. Its types are 

 mostly Amazonian and among the oldest 

 found on the continent. This fauna has cer- 

 tainly entered over the Atrato-San Juan route. 

 The fishes of these two rivers are very similar 

 and many species are common to both. The 

 channel-fishes of the Atrato, however, have 

 not succeeded in crossing over to the San Juan. 

 They have spread thence to all the rivers south 

 to Esmeraldas. Those of the Chepo and Tuyra 

 basins of Panama have evidently also come 

 from the Atrato. Dr. Meek says:^ 

 ... it is quite evident that strictly South Amer- 

 ican migrants in comparatively recent times did 

 not go far beyond the Canal Zone, and that most 

 of these are lowland forms which came from the 

 streams on the Atlantic side of Colombia to the 

 Pacific side after the last gap (Atrato-Tuyra) 

 here between the two oceans was closed. We find 

 Curimatus, Ctenolucius and Gasteropelecus and 

 other Colombian Atlantic forms in streams oppo- 

 site the Eio Chagres but not in it. Some Loricar- 

 ids occur in these streams and also in the Rio 

 Chagres, but these appear to us to have probably 

 crossed from the Pacific side streams to the 

 Chagres and not to have migrated from the rivers 

 of Colombia to the Chagres direct. 



The Ecuadorian sub-province is character- 

 ized by its increasing aridity, which begins 

 immediately south of the cross-ridge of 

 Esmeraldas, is intensified below Guayaquil as 

 shown by the Desert of Tumbez, and culminates 

 in the desert regions of Peru. In the long 

 dry season all of the rivers dwindle to mere 

 puddles. Under these unfavorable conditions 



2 Publications, Field Museum of Natural His- 

 tory, Zoological Series, Vol. X., No. 10, 1914, p. 

 134. 



