A MONOGRAPH OF THE BATS OF NORTH AMERICA. 



65 



the last molars as well as in the proportions of the liypoconid. In the 

 number and arrangement of the premolars and molars, as Avell as in 

 the shape of the nppcr premolar, Antrozous is strikingly like Dast/pterus. 

 In the number of incisors in the lower Jaw, in the free lower lij), in the 

 manal formula, in the disposition for the nostril to bear a vertical in- 

 ternarial ridge and the upper border of the muzzle to exhibit a trans- 

 verse outgrowth, in the presence of a hem on the pollical side of the 

 second metacarpal bone, Antrozous recalls the Phyllostomida'. 



In the restriction of the lower incisors to four in a family where the 

 dominant number is six it is of interest to note that in Nyctinomous 

 hrasiliensisthe third incisor on each side is rudimental or may be lost, 

 thus reducing the number from six to four, the number normal to N. 

 macrotia and Proniops. 



Peters has called attention to the affinity between Antrozous and 

 Nyctophilus. I have lately been able to make a comparison between 

 these genera, so far removed in geographical range. The following 

 characters have not been used before in classification : 



A)itro:oiis. 



Transverse muzzle-band oontiiuious with 

 the lower margin of the nostril ; thus 

 the depression of the nostril is con- 

 tinuous with the [/move above the 

 nostril. 



External basal lobe of the auricle without 

 an inner fold. 



Terminal cartilage of the fifth digit bifid, 

 the somad lobe prolonged; incon- 

 spicuous accessory cartilage. 



The nerves in the fourth interdigital 

 unequal, the post-digital much the 

 longer. 



Protocone small, not extending beyond 

 the paracone. 



Upper premolar scarcely fiuted, witliout 

 cingulum on palatal surface. Lach- 

 rymal process small, no supraorbital 

 ridge ; facial vertex convex. 



Nyctophilus. 



Transverse baud is continuous with the 

 upper margin of the nostril ; thus the 

 depression of the nostril is cut off 

 from the j;(< above the nostril. 



External basal lobe of the auricle with a 

 cons])icHous inner fold. 



Terminal cartilage of the fifth digit 

 acicular; conspicuous accessory car- 

 tilage. 



The nerves of the fourth interdigital 

 space of er[ual length and arise on 

 same level. 



Protocone large, extending entire length 

 of tooth. 



Upi)er premolar deei)ly iluted, with cin- 

 gulum on i)alatal surface. Lachry- 

 mal i)rocess and supraorbital ridge 

 trenchant ; facial cortex fiat or con- 

 cave. 



The shapes of the premolars and molars, (he jiresence of the acces- 

 sory cartilage to the fifth digit, the number of teeth in the lower jaw, 

 are characters which ally J^yciophUus to the vespertilionines and place 

 it near Synotus, while no characters suggest its affinity to the phyllos- 

 tomines, unless the sliape of the nose-leaf be held to be of this value. 

 In common with Corynorhinus and Antrozous, the muzzle glands unite 

 back of the nose-leaf. On the whole, I incline to the oi)inion that Sycto- 

 philus did not arise from a stem distinct from that from which 

 sprung the vespertilionines, wliile Antrozous arose from the phyllosto- 

 441— No. 43 5 



