2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. im 



Puerto Rico and the Virgin Islands. Of these, Ardops may be related 

 most closely to Ariteus, from which it differs principally in having 

 a broader rostrum, narrower mesopterygoid fossa, distinctive 

 sphenoid-basioccipital region, a small, peglike M3 (lacking in Ariteus), 

 and the absence of any trace of a metaconule on the first lower molar. 

 Ardops presently is known from Dominica, Martinique, St. Lucia, 

 and St. Vincent in the Windward Islands, and from Guadeloupe, 

 Montserrat, and St. Eustatius in the Leeward chain. Bats of this 

 genus probably occur also on Nevis and St. Christopher [St. Kitts], 

 and possibly elsewhere in the Lesser Antilles, but doubtfully in the 

 Greater Antilles, where they are replaced by the genera mentioned 

 above. 



Other workers have commented on the slight differences ascribed 

 to the four nominal species of Ardops. G. M. Allen (1942, p. 19), for 

 example, noted that the "slightly differing" species were of "similar 

 appearance." Hall and Kelson (1959, p. 142) wrote: "The currently 

 recognized species are separated from each other seemingly on little 

 more than slight differences in size and should possibly be regarded 

 as actually constituting but one species." After study of the available 

 material, taking into account individual and secondary sexual varia- 

 tion (females average larger than males — strikingly so in some popula- 

 tions), we recommend arranging the named kinds as subspecies of 

 a single species, Ardops nichollsi, because (1) the differences between 

 them are slight and quantitative in nature, (2) overall variation 

 does not exceed that described as occurring in a number of other 

 polytypic species of stenodermine genera, and (3) such a classifica- 

 tion best reflects the similarities and obviously close affinities of the 

 included taxa. 



Among the subspecies, A. n. nichollsi of Dominica is the smallest 

 (possibly excepting the population on St. Vincent, known to us by a 

 single battered specimen in spirits from which the fragmentary skull 

 has been removed). In order of increasing size, the other recognized 

 races are distributed on St. Lucia (A n. luciae), Guadeloupe (A. v. 

 annectens), Martinique (subspecies newly named herein), and on 

 Montserrat and St. Eustatius (A. n. montserratensis) . A continuum 

 in size can be demonstrated among the five subspecies but the contin- 

 uum is not clinal, suggesting that the various insular populations 

 have adapted independently to conditions prevailing on individual 

 islands. Some size relationships are illustrated in figures 1 and 2 

 and in table 1. 



Among 29 skulls with complete maxillae and mandibles, we find 

 only two that do not possess the full complement of teeth (2/2, 1/1, 

 2/2, 3/3 = 32) typical of Ardops. Both of these, a female from St. 

 Eustatius and a female from St. Lucia, lack the peglike M3 on the 



