e individuals lacked a dorsal pattern, but by day many of these
individuals developed dorsal stripes.

_Cranial Osteology._--The skull of _Hyla elaeochroa_ is slightly wider
than it is long, and flat. The premaxillary is small and bears 10 to
15 teeth (mean for 9 specimens, 12.3). The alary process of the
premaxillary is small, vertical, and slightly concave posteriorly.
Ventrally, the premaxillary is partially united to the prevomer by
ossification. The maxillary is slender and bears 70 to 82 teeth (mean
for 9 specimens, 74.3). The pars facialis of the maxillary is
laterally convex and is about twice as high as the pars dentalis.

The nasal is large, robust, anteriorly truncate, but pointed
posteriorly in dorsal view. The nasal comprises about 45 per cent of
the total length of the skull. There is an anterior cartilaginous
septum nasi separating the two nasals; the latter overlap the
sphenethmoid posteriorly. Each nasal bears a shallow concavity in the
midlateral side and lacks a maxillary process. Dorsally, the
sphenethmoid is wider than long, roughly pentagonal in shape; the
frontoparietal is elongate, smooth, and bears a small anterior
supraorbital process. The sphenethmoid and frontoparietal form the
anterior margin of the frontoparietal fontanelle; the fontanelle is
narrow anteriorly and wider posteriorly (Fig. 5B).

The entire distal surface of the prooetic is in contact with the
posterior arm of the squamosal. A narrow cartilaginous crista parotica
is visible dorsally in some specimens. The squamosal is broad
posteriorly but its anterior arm is slender and not in contact with
the maxillary.

TABLE 5.--Geographic Variation in Size and Proportions in Males of
_Hyla elaeochroa_. (Means in parentheses below observed ranges.)

==========================================================================
| |Snout-vent| Tibia | |
| | length | length/ |Tympanum/|Foot length/
Locality | N | (mm.) | snout-vent | eye | snout-vent
---------------------+----+----------+------------+---------+-------------
Nicaragua: El Recreo | 9 | 28.0-30.3| 0.51-0.57 |0.47-0.59| 0.39-0.54
| | (29.3) | (0.55) | (0.51) | (0.41)
| | | | |
Costa Rica: Tilaran | 21 | 28.8-33.6| 0.47-0.57 |0.48-0.65| 0.40-0.46
| | (30.6) | (0.52) | (0.59) |