Journal 22 km E (by tmz) Trinidad de Doto, San Jose Province, Costa Rica 2600 m. 18 July The Scotinomys here are presumably teguina (Alston's brown mouse), the Reithrodontomys of this region include simichrasti (an abundance of black dorsally which largely obscures the cinnamon ground color); braurostris (from the Cordillera Central of Costa Rica); mexicanus (usually arbor. of humid oak-pine forest but also occurs in rain forest ^) semi-arid deciduous forests). tail is unicolor * rarely white tipped; creper (upper parts tawny or cinnamon-orange heavily interspersed w/ black hairs^); tail unicolor [illegible] second & well-haired): The Oryzomys include: alforoi (195- Total L. color underparts tail alforoi 195-257- variable white fulvescens 168-235 buff->tawny white->luff dk brown pale brown caliginosus 196-240 russet->tawny paler but not sharply so devius 335-360 dark tawny most of the animals caught today were in the mature forest. I caught 27 Heteromys + a juvenile of the same species. A number of specimens were prepared as study skins, with tissue taken - these included midipes, several Reithrodontomys and an Oryzomys (probably alforoi). The Scotinomys, Oryzomys (large one - devius) and several Heteromys were saved for [illegible] in San Jose. One Heteromys f had v. distended mammal and was around peak estrus. Another had small embryos which were saved in formol^n. this one had v. smaller uteri. An embryo set was also seen in the