184 Proceedings of the Biological Society of Washington. 



M. calif ornicus ; ears and feet similar in shape but distinctly shorter than 

 in M. lucifugus and about as in M. californicus ciliolabrum. 



Measurements of type (in flesh). — Total length, 82 mm.; tail, 39; hind 

 foot, 8; forearm, 30.5; extent of wings, 225. 



Skull. — Distinctly smaller and more flattened than in M. lucifugus and 

 more closely resembling that of M. californicus, but even more flattened 

 than in that species. 



Skull measurements. — Basal length from nasal notch to occipital foramen, 

 10.4; width of brain case, 6.8. 



Remarks. — The specimen from Brandon, Vermont, is a female and 

 slightly more richly colored and larger than the male (type); this size 

 difference between the sexes being commonly the case in this genus. 

 It also differs from both the Maryland specimens in having a distinctly 

 more flattened brain case and longer and proportionately heavier rostrum. 

 Should other specimens from Vermont or the surrounding area agree with 

 the Brandon example in the formation of the skull it may be necessary to 

 distinguish it as a subspecies. 



This interesting small species is most closely related to the californicus 

 section of the genus but appears to have been overlooked up to the present 

 time largely through its general color resemblance to M. lucifugus. It 

 may be at once distinguished from that species by its forearm, which is 

 about 4-8 mm. shorter. The skulls of this species are a trifle larger than 

 those of typical californicus, from middle California, with top of brain 

 case a little more flattened. They agree most closely in size and skull out- 

 line with examples of M. californicus ciliolabrum from South Dakota, and 

 from Graybull, Wyoming, but have more flattened skulls and smaller 

 teeth. 



