1908.] UR. KNUD ANDERSEN ON" BATS. 273 



(average 32-2); zygomatic width 18-8-20-2 mm, (average 19-4); 

 maxillary tooth-row 10*7-12-2 mm. (11'7); forearm 64-73-5 mm. 

 (70-2J. 



General characters. — This is the first of the three very closely 

 related southern ra.ces of A. jamaicensis described in this paper. 

 The southern group {A. j. Iitu7'atus, j^nlniarum, prceceps) differs 

 from the northern (^4. j.parvi2)es, yucatanicus, jamaicensis, cequa- 

 torialls) chiefly in the following points : — 



The angular notch in the posterior margin of m-, between its 

 cusps 5 and 7, is rather rarely as well marked as in A. plani- 

 rosiris ; generally (in about 90 p. ct. of 68 skulls examined) it is 

 either noticeably reduced or completely filled up ; in the latter 

 case the bulk of m" has been increased by an area more or less 

 corresponding to that of the missing m^ By advancing age the 

 sagittal crest of the skull is produced considerably forward, the 

 supraorbital ridges directed almost straightly outward, the post- 

 orbital and anteorbital processes conspicuously developed, — as 

 described in detail and figured on p. 248. The dimensions are, 

 generally, in every respect lai-ger, sometimes (especially in 

 A.j. liturat'us a,nd 2}cdviaruvi) considerably larger. The colour in 

 full-grown individuals with unworn or practically unworn teeth 

 is, most often, of the dark type, rather often, however, light ; at 

 a higher age the majority of individuals are light-coloured. The 

 supraorbital stripes are, as a rule, well marked, often veiy strong, 

 rather rarely faint or obsolete ; tlie infraoi'bital stripes not rarely 

 well developed. 



A.j. lituratus, javiaicensis, and cequatorialis. — There is very 

 rarely any difliculty in (\i&c\-imvaa,t\i\g A . j . Iitu7'atus from A.j. 

 jamaicensis. The skull averages almost 4 mm. (14 p. ct.) longer, 

 and l"5-2 mm. (14 p. ct.) broader, the tooth-rows 1*4-1 '7 mm. 

 (about 14 p. c;t.) longer than in A.j. jamaicensis ; the forearm and 

 metacarpals average nearly 10 mm. (16-18 p. ct.) longer. Even 

 the very smallest individuals of A. j. litttratus have, almost always, 

 the skull and teeth in some direction or other more heavily built 

 than in the largest individuals of A. j. jamaicensis. When, 

 further, it is taken into consideration that there is absolutely no 

 overlapping of the geographical areas occupied by these two races, a 

 confusion becomes practically impossible. 



A.j. cequatorialis is generally a little larger than A.j. jamai- 

 censis, and, consequently, comes a little nearer to A.j. lituratus 

 in size ; but the average difierence between ceqitatorialis and 

 lituratus is still very great, the absolute difference as a rule well 

 marked. A. j. lituratus extends into the area inhabited by 

 A.j. mquatorialis, but individuals which cannot be referred with 

 certainty to either the one or the other form seem, even in the 

 region common to both, to be very rare. 



A . j. lituratus cannot be separated as a distinct species. First, 

 individuals do occur, though rarely, that cannot, by their characters 

 alone (i. e. apart from their habitat), be discriminated with cer- 

 tainty from some individuals of A. j. cequatorialis a,nd jamaicensis ; 



18* 



