356 On a Natural Arrangement of the Chiroptera. 



The last-described character, derived from examination of 

 the minute structure of the hairs, is a valuable one. I was 

 much satisfied to find that it agreed with the system of classi- 

 fication I had sketched out previously. Thus the proper posi- 

 tion of Rhinopoma among the Emballonuridge is further shown, 

 and the close affinity of Noctilio to the Moi-mopes additionally 

 demonstrated. I have arrived at this generalization from ex- 

 aminations of the minute structure of the fur in almost every 

 genus of the Vespertilionine,, and in most of the genera of the 

 Emballonurine alliance*. 



Magnified hair of Cori- 

 norhimis Townsendi } tyip\- 

 cal of the Vespertilio- 

 nine Alliance. 



Magnified hair of 

 Mormops megal&phyUa, 



typical of the Emballo- 

 nurine Alliance. 



Distribution of the Families of Chiroptera. 



As I have remarked above, the lines of descent correspond 

 very closely to the geographical distribution of the Chiroptera. 

 Thus the Nycteridee and Rhinolophida? are confined to the 



give the deceptive appearance of growing thicker and thinner at intervals. 

 The arrangement of the scales upon the hair presents almost as much 

 variety as the phyllotaxis of plants. Thus they are, natnrany as it were,, 

 alternately disposed ; hut opposition and whorling are frequently seen ~ r 

 they may be specially attached to the broad surfaces, or to the borders, or 

 to both, in four or more series. The optical section of the scales often 

 gives the appearance of sharp spines besetting the sides of the hairs. 



" It is a curious fact that imbrication, with the tips of the scales in an; 

 oblique line, should mark one, and a symmetrical disposition with trans- 

 verse lines characterize the other of the two alliances into which Mr. 

 Dobson proposes to divide the families of Chiroptera." 



* I have examined the microscopic structure of the hair in the fol- 

 lowing genera : — 



}. VespefrtiUomdw. Mhnopterus, Natalus, Thyroptera, Murina r Ohalino- 

 lobus, Vespertilio, Vespemgo, Atalapha, Scotophilus, Plecotus, Corino- 

 rhinus, Otonycteris, Nyctophilia, Antrozous. 



2. Niietmcltp. Nycteris, Megaderma. 



3. Rhinolophiilcr. Rhinolophus, Phvllorhina, Rhinorrycteris, 



4. Embattonuridee. Furim, Diclidurus, Coleura, Taphcwous, Rhvncho- 

 nycteris, Noctilio, Rhinopoma, Nyctmomus, Molossus, Mystacina. 



5. PhtyMostomidee. Chilonycteris, Mormops, Carollia, Rhinophvlla, 

 Trachyops, Glossophaga, Monophyllus, Vampyrus, Centurio, Aritibeus, 

 Brachyphylla, Desniodus. 



