266 DR. KNUD ANDERSEN ON BATS. [Apr. 7, 



nor in colour is there any difference between A . j. jatnaicensis and 

 its closest allies, A.j. i/ucatanicios a,nd 2ycirvipes; but there is a 

 distinct average difference in size, small though it is. The details 

 have been briefly commented upon in the desciiptions of the two 

 latter races (pp. 261 and 263), and are expressed in the table of 

 measurements, p. 284. 



Specimens from different localities. — A. j. jamaicensis covers a 

 much wider area than the two foregoing i-aces (^yucatanicus, 

 pm-vijyes). It is distributed over the whole of Central America, 

 including the outlying small islands (St. Andrew's, Old Providence), 

 and S. Mexico, at least as far as Morelos ; further, over Jamaica, 

 San Domingo, Porto Rico, and the smaller islands east of this 

 latter, at least as far as St. Kitts. I have carefully compared 

 specimens (skulls, spirit-specimens, skins) from all these places, 

 and am unable to find the slightest indication of a difference. It 

 is very easy, indeed, to contrast a smaller-skulled (smaller-toothed) 

 individual from one place with a larger-skulled (larger-toothed) 

 from another continental place or another island, a smaller -winged 

 with a larger -winged, a darker-coloured with a lighter-coloured, 

 or a specimen with short with a specimen with long interfemoral. 

 When material is scarce, differences of this kind may very easily 

 lead (and, in fact, have led) to separation of different forms or 

 even species ; but whenever the various localities have been 

 represented by a sufficiently extensive series in the material 

 examined by me (as has been the case with Central America, 

 S. Mexico, Jamaica, Porto Rico, St. Andrew's Island, Old Provi- 

 dence Island), I have found the range of individual variation to 

 be precisely the same within each particular locality ; there is no 

 difference whatever in structure nor in coloration, and there is 

 not even an average difference in size. 



In the comparative table of measurements below (p. 269) the 

 specimens have been arranged under seven headings, viz.. Central 

 America (Panama,, Nicaragua, Honduras, Ruatan I., Guate- 

 mala), S. Mexico (Campeche, Chiapas, Tehuantepec, Oaxaca, Yera 

 Cruz, Morelos, " Mexico '■•■), Jamaica, Porto Rico, San Domingo, 

 St. Kitts, St. Andrew's and Old Providence Islands. From each of 

 these seven areas are given the minimum, maximum, and average 

 measurements (the latter not for the few available specimens 

 from San Domingo and St. Kitts). The table shows the complete 

 accordance in the size of individuals from these seven areas. 



To prevent wrong identification it is important to emphasise 

 that Central America is inhabited hy tioo races, which ought not 

 to be (but hitherto have always been) confused, viz. the smaller 

 (truly indigenous) A.j. jamaicensis and the larger A. j. ijahnartmi 

 (an immigrant from south). 



Specimens examined. — 105 specimens (58 skins) and 76 skulls, 

 from the following localities : — 



British Miiseum : — Nicaragua : Corinto (1). — Honduras : Half- 

 Moon Key (1); Ruatan Island (5). — Guatemala: Duenas (1). — 

 "Mexico" (1). — St. Andrew's Island (3). — Jamaica (17). — San 



