VOL. IV.] Nyclinoimts MoJiavensis. 36 



1 



As the first two, however, are described from essentially the 

 same region, it would seem impossible to treat them as sub- 

 species; and as our specimens without exception agree with 

 viohave7isis in the characters by which it is said to diflfer from 

 fe?norosacacs, it seems best to recognize the two as valid species 

 until further comparison is possible. 



The specimens taken February 27 were all procured from 

 the shutters of one window on the western side of ibe building, 

 and consisted of males and females in about equal numbers. A 

 second visit to the Court-house on March 3 resulted in the cap- 

 ture of sixty-seven additional specimens. Of these, thirty-two 

 were taken from behind one shutter again on the west side of 

 the building, and consisted, as before, of both sexes about 

 equally represented. The rest of the second catch, thirty-five in 

 number, were taken from behind four different shutters on the 

 east side of the Court-house, and proved on examination to con- 

 sist of females exclusively. This furnishes additional evidence 

 that under certain circumstances the sexes congregate separately. 



Several specimens of this bat have since been taken on the 

 University Campus, and at the Hopkins Seaside Laboratory at 

 Pacific Grove. We have also had the privilege of examining a 

 specimen collected at San Diego, Cal., by Mr. C. H. Marsh. In 

 this the lower incisors were 3-3, distinctly bilobate, and in gen- 

 eral proportions, and shape of ear, it agreed with our specimens. 



Le Conte has already called attention to the variation in the 

 number of lower incisors in Nyctinomus brasiliensis i^' Rhinopoma 

 caroline7ise"), as out of fifteen individuals examined by him 

 " one had no incisors on the lower jaw; two had five; three had 

 four, and the rest six."* The same variation obtains in mo- 

 havensis. Merriam describes the lower incisors as 2-2, not dis- 

 tinctly bifid. But the normal arrangement appears to be 3-3, 

 all distinctly bilobate. Thus in forty-five specimens examined 

 as to this character, 24 specimens have 6 lower incisors; 9 have 

 5, and 12 individuals have 4. The outer incisor when present is 

 very small, and so crowded forward as to occupy a precarious 

 position in front of the canine, a fact which may account for its 



* Observations oa the North American Species of Bats, John I,e Conte 

 Proc. Acad. Nat. Sci., Phila. , 1859, pfige 43'. 



