28 CHIROPTERA. 
finger is folded against the upper surface of the metacarpal. But the most remarkable 
character is the possession of a peculiar glandular pouch opening on the upper surface 
of the antebrachial part of the wing-membrane. ‘This sac, which secretes a strongly 
smelling matter, has been shown by Professor Reinhardt to be developed only in the 
males, remaining quite rudimentary in the other sex*; and further observation has 
confirmed his suggestion that the structure is to be regarded as a secondary sexual 
character, it being, in fact, strictly analogous to the frontal sac of Phyllorhina and the 
gular pouch of Taphozous}. Its position in the antebrachial membrane varies in the 
several species, and has been used by Professor Peters to diagnose his genera Sacco- 
pteryx, Peropteryx, Cormura, and Balantiopteryx}; but these variations will here 
be more conveniently used as specific characters to differentiate the three recorded 
Central-American forms :— 
1. S. dilineata. Opening of wing-pouch along the forearm, which measures 1"85. 
Fur dark brown above with two longitudinal dorsal white streaks, greyish- 
brown beneath. 
2. 8. canina. Opening of wing-pouch near the edge of the antebrachial mem- 
brane, directed outwards. Forearm 1-80. Fur blackish-brown, somewhat 
lighter below. 
3. 8. plicata. Opening of wing-pouch in the middle of the antebrachial mem- 
brane, directed inwards. Forearm 1°70. Fur dark brown, lighter below ; 
posterior margin of the wing-membrane white. 
1. Saccopteryx bilineata. 
-Urocryptus bilineatus, Temminck, Van der Hoeven’s Tijdsch. v. Natur. Gesch. p. 33, figs. 3, 4(1838-9, 
descr. orig.)'; Mon. de Mamm. ii. p. 301°. 
Saccopteryzx bilineata, Peters, Monatsb. Ak. Berl. 1867, p.471°; Dobson,Cat. Chir. Brit. Mus. p. 372°. 
Hab. Guatemaua, Vera Paz, Sta. Lucia (Salvin, Mus. Brit.4).—Cotomsiat; Gutana!; 
BRAZIL‘. 
Of this species Mr. Dobson remarks that he is doubtful whether it will not prove to 
be merely a large variety of the Brazilian S. deptwra (Schreber) with more marked white 
dorsal lines. He adds, ‘““I am, however, unable to settle this question, owing to 
insufficiency of material to work upon, and therefore prefer for the present to recognize 
two species, in accordance with the views of other zoologists, and especially in deference 
to those of Professor Peters, who has worked out this group with great care’4. Mr. 
Salvin’s specimen was shot at midday when clinging to the stem of a tree in the virgin 
forest near Santa Lucia, in the Pacific coast-region of Guatemala. 
* Ann. & Mag. Nat. Hist. (2nd ser.) iii. pp. 886-888. 
tT Cf. Dobson, P. Z.8. 1873, pp. 241-252, ~ Monatsb. Ak. Berl. 1867, pp. 470-481. 
