6 BIRDS OF SOUTHWESTERN MEXICO. 



extend tbrough all the families, I wrote him for an explanation, and got 

 the following reply: "I regret to be unable to tell you certainly which 

 are the biographies and notes that I forwarded to the Institution. Al- 

 most all my books and papers were carried off in 1871 during the pillage 

 of my house in Juchitan, and I cannot verify the dates of my invoices to 

 the Institution." 



In December, 1871, Professor Sumichrast was obliged to leave Juchi- 

 tan on account of the revolutionary state of the country, and made his 

 residence at Santa Efigenia, which he writes me is " a hacienda thirty 

 leagues or so south of Tehuantepec, at the foot of the Cerro de la Gineta, 

 and on the border of the State of Chiapas." Tapana, a locality often 

 given, he says is " a village in the neighborhood of Santa Eflgeuia." 



All communications from him are designated by quotation-marks. 



"NOTES ON THE GEOGRAPHICAL DIVISION OF THE BIRDS IN THE ISTH- 

 MUS OF TEHUANTEPEC. 



"The contraction of the American continent between the ninety- 

 fourth and ninety-fifth degrees of longitude west from Greenwich forms 

 what is called, quite improperly perhaps, the Isthmus of Tehuantepec, 

 whose width between the mouth of the Eio Coatzacoalcos and the Bay 

 of Ventosa is about one hundred and eighty miles. 



" In a physical point of view, the isthmus may be considered as divided 

 into three parts, first, an eastern, extending from the Gulf of Mexico 

 to the Puerta ; secondly, a central, from the Puerta to the Chi vela; and, 

 thirdly, a western, from the Chi vela to the Pacific. The eastern part, 

 formed principally of alluvial land and watered by the Coatzacoalcos 

 and its affluents, has its largest portion covered with thick and damp 

 forests, whose vegetation rivals the greatest beauties of tropical nature. 

 The central region presents an undulating surface, embossed with innu- 

 merable lomas, or hills, which, rising gradually, unite on the western 

 side with the mountains of the Sierra de los Mijes, and, toward the east, 

 with those of the Sierra de Chimalapa. Although watered by numer- 

 ous streams, it presents, nevertheless, but a scanty vegetation, essen- 

 tially characterized by oaks on the side of Sarabbia, and palm-trees on 

 the plateau of Chinela. The western division, or plains of the Pacific, 

 is very dry, and its vegetable physiognomy presents a striking contrast 

 to the rich plains on the Atlantic slope. Of the few rivers which flow 

 through it, the most important are the Tehuantepec, Juchitan, Chicapa, 

 and the Ostula. These are so low during part of the dry season that 

 the inhabitants of the villages and ranchos situated on their banks have 



