546 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
line is not straight but serrate or with narrow extensions toward the 
middorsal area. 
In the simpler patterns, two dark stripes extend from the occipital 
region, where they are united posteriorly to the base of the tail, ter- 
minating there more or less abruptly. Between them is enclosed a 
median light stripe. In some cases the dark stripes are discontinu- 
Figure 58.—Bolitoglossa mexicana Duméril and Bibron: 4, U.S.N.M. No. 116077; B, 
U.S.N.M. No. 116074; C, U.S.N.M. No. 116079; D, U.S.N.M. No. 116082. All from 
near Palenque, Chiapas. 
ous or enclose within them light spots sometimes arranged in a linear 
fashion. 
A further type of variation is seen in those in which the two dark 
stripes are fused to form a single broad, median, dark stripe, which is 
modified either by being broken into irregular spots or by having 
extensions, along the costal grooves, which meet the dark lateral color. 
Finally, certain specimens are simply cross-barred, the bars some- 
times broken, sometimes fused medially or on each side in the position 
of the hypothetical two dark stripes. 
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