_=Pteronotus psilotis=_ (Dobson).--A total of six specimens from two localities in southern Sinaloa provide the first records from the state and are the northernmost records in western México. The two localities are: ½ mi. S Concepción, 250 ft. (84987-90); 1 mi. W Matatán (84985-86). The two individuals from the last-mentioned place extend the known range of the species approximately 275 miles north-northwest from a locality 7 mi. W, ½ mi. S Santiago, Colima (Anderson, 1956:349), and place the limit of the known distribution of _P. psilotis_ farther to the north in western México than in the eastern part of the country. We follow Burt and Stirton (1961:24-25) in use of the generic name _Pteronotus_ for this species. The two specimens from 1 mi. W Matatán were shot at late dusk as they foraged with other bats, presumably of the same species, low over water at the place where the Río San Antonio joins the larger Río Baluarte. The four individuals from ½ mi. S Concepción were captured in mist nets stretched across the Río de las Cañas at the Sinaloa-Nayarit border, and were taken shortly after dark at heights of three feet or less above the water. Our six specimens all are males. Five are in the reddish color phase and one is in the brownish phase. Average and extreme measurements of the six males, which average slightly smaller than specimens examined from Colima and Guerrero, are as follows: total length, 66.8 (65-69); length of tail, 16.3 (15-18); length of hind foot, 11.8 (11-12); length of ear from notch, 16.9 (16.5-17.0); length of forearm (dry), 41.5 (40.6-42.4); weight in grams, 8.3 (6.9-9.8); greatest length of skull, 15.4 (15.2-15.5); zygomatic breadth, 8.3 (8.2-8.4); interorbital constriction, 3.4 (3.3-3.6); mastoid breadth, 8.7 (8.6-8.8); length of maxillary tooth-row, 5.8 (5.8-5.9); breadth across M3, 5.4 (5.3-5.6). _=Sturnira lilium parvidens=_ Goldman.--The first specimens to be reported from Sinaloa are as follows: 32 mi. SSE Culiacán (61087); 1 mi. S El Dorado (75207); Pánuco, 22 km. NE Concordia (85648-50). The three bats from the last-mentioned locality were caught after midnight in a mist net stretched across a road adjacent to a nearly dry stream bed. The vegetation in the vicinity of the net consisted mostly of dry weeds and grass along with some low shrubs, but a tree-filled canyon was about one-fourth mile above the net. We lack details about the capture of the other two bats. _S. l. parvidens_ has been reported only once from farther north in western México than Sinaloa. Anderson (1960:7) recorded five specimens from along the Río Septentrión, 1½ mi. SW Tocuina, Chihuahua.