1908.] DR. KNUD ANBERSEN ON BATS. 281 



and 'palmarimi, some individuals are of the dark, others of the 

 light coloui' type, some have the sujoerciliary stripes less distinct 

 or even obsolete, while others (and these the majority, in Costa 

 Rica and elsewhere) have them well marked or even very strong ; 

 the infi-aorbital are always less pronounced than the supi-aorbital 

 stripes ; the colour characters given by Allen must therefoi-e be 

 left out of consideration when judging the validity of "^J. inter- 

 medius." — When Allen found the type of A. intermedius "appa- 

 rently intermediate [in size] between A. pcdmarum und A. per- 

 sjncillatus" it is only because the specimen happens to be a small- 

 sized individual ; in the series from the type locality and adjoining- 

 regions of Central America examined by myself, there are sevei'al 

 examples as small as (and slightly smaller than) Allen's specimen, 

 but these represent unquestionably the minima of size ; the other 

 extreme is shown by the following measui'ements of the forearm : 

 in two specimens from Chiriqui 70-5 and 72 mm., two from Costa 

 Rica 71 and 73 mm., two from Nicaragua 71 and 73 mm., three 

 from Guatemala 70, 72, and 72-5 mm. ; the rest of the individuals 

 are, of course, intermediate in size between these two extremes. 

 Thus, also the size-character given by Allen must be dropped. — 

 There remains the shape of the skull ; but as pointed out above 

 (p. 248, text-figs. 50, 51), this " remarkably convex " braih-case 

 (sagittal crest produced forward, supraorbital ridges directed 

 almost straightly outward, well developed post- and anteorbital 

 processes) is an age character in A . j . lituratics and jxilmat-um, 

 not a specific character ; it is by no means peculiar to Central 

 American individuals, but occurs, to the same degree, in individuals 

 from Paraguay, Brazil, Colombia, Venezuela, Trinidad, &c. I have 

 carefully compared Central American (and Mexican) specimens 

 with Trinidad and Venezuelan specimens of A. j. jJcdmarum., and 

 am unable to find any difierence whatever. 



In 1902 {I. s. c), Outran! Bangs recorded three "A. intermedius" 

 from Boj;ava, Chiriqui, one old $ , one youngish c? , and one 

 youngish 2 j and wrote : — " The younger specimens are more 

 sooty, with the facial stripes less well indicated, and have smaller 

 skulls .... The difference in size is great, and the skulls do not 

 show the degree of immaturity that one would expect with the 

 diff'erence in size." The explanation is this : the two youngish 

 specimens (provided they are really full-grown) were, no doubt, 

 A . j. jamaicensis, the old female an A . j. ■pal'i^iariim. It cannot 

 be too strongly emphasised that Central America and S. Mexico 

 are inhabited by two forms of A . jamaicensis — the one, and small, 

 is the truly indigenous race, A . j. jamaicensis, occurring also in 

 Jamaica, San Domingo, Porto Rico, eastwards at least to St. 

 Kitts; the other, and larger, is A. j. jxdmarum (or, if preferred, 

 A.j. lituratiis), which has come from south, — two forms which 

 till now have been mixed together. As the two races are not 

 perfectly differentiated " species," one cannot expect them to be 

 separable in all particular instances ; but many individuals can 

 be identified at a glance, and whenever the external characters 



