Quast 1948 Perognathus spinatus 1 April 10 Punta San Felipe, 50+ ft, Baja California Four ♂, six ♀ in rocky mountainside east of camp. Traps set mainly on rises between gullies and near burrows beneath Encelia bushes. Animals caught at night in live traps set ap- proximately 30 ft apart and were accompanied by four Perognathus formosus and two Peromyscus crinitus. Traps set at least 100 yds from desert association. April 12 9 mi W. Punta San Felipe, 200+ ft, Baja California One caught on decomposed granite hillside with one Perognathus formosus and a Peromyscus crinitus. 50 live traps were set. #44. April 15 Cerrada Centinela 300 ft 13 mi WSW Mexicali; Baja California Four caught in live traps baited with ground whole corn in small meandering wash in alluvial material below rock mountainside. Specimens put up by Tevis and Murray and cataloged under this date. April 16 One ♂ + one ♀ caught in alluvial material in live traps baited with ground whole corn at night of the 15th (#54 + 59). April 18 Cerro Prieto 30 ft 20 mi SSE Mexicali, Baja California Four caught in rocks (lava) within 50 feet of mesquite-sand association.