The two subspecies of _H. microcephala_ are identical in call pattern and agree closely in duration of notes, although those of the nominate subspecies tend to be slightly longer. _Hyla robertmertensi_ is distinctive in call pattern in that it is the only species having a paired primary; the duration of the primary is completely overlapped by that in the other species, but the secondaries tend to be the shortest in the group. The call patterns of _H. phlebodes_ and _H. sartori_ are identical and the range of duration of notes of _phlebodes_ completely overlaps that of _sartori_, although both the primary and secondary notes of the latter tend to be somewhat shorter (Table 5, Pl. 16). _Fundamental frequency._--This parameter was analyzed for the primary notes. It was measured for the secondaries as well and was found to differ in magnitude in the same way as the primary note. In a few examples of both subspecies of _H. microcephala_ a high primary note, in which the fundamental frequency is exceptionally high, is sometimes emitted (Fouquette, 1960b). None of these notes was used in this analysis; only the fundamental frequencies of normal primary notes are compared (Table 5, Fig. 7). Table 5.--Comparison of Normal Mating Calls in the Hyla microcephala Group. (Observed Range Given in Parentheses Below Mean; Unless Otherwise Noted Data Are for Primary Notes.). ----------------+--+---------+---------+-------------------+-------------- | |Dominant | Funda- |Duration of notes | Repetition | | | mental| (seconds) | rate of Species |N |frequency|frequency+---------+---------+ secondaries | | (cps) | (cps) | Primary |Secondary|(notes/minute) ----------------+--+---------+---------+---------+---------+-------------- _H. m. |44| 5637 | 205 | 0.13 | 0.10 | 268 microcephala_ | |(5150 |(184-244)|(0.11 |(0.05 | (192-353) | | -5962)| | -0.16)| -0.14)| | | | | | | _H. m. |47| 5772 | 220 | 0.11 | 0.09 | 283 underwoodi_ | |(5177 |(192-275)|(0.05 |(0.06 | (197-384) | | -6200)| | -0.15)| -0.11)| | | | | | | _H. |25| 5388 | 162 | 0.09 | 0.04 | 418 robertmertensi_| |(5150 |(140-178)|(0.07 |(0.03 | (368-570) | | -5785)| | -0.11)| -0.06)| | | | | | | _H. phlebodes_ |34| 3578 | 148 | 0.11 | 0.07 | 284 | |(3220 |(125-158)|(0.07 |(0.04 | (210-350) | | -4067)| | -0.16)| -0.12)| | | | | | | _H. sartori_ |10| 3217 | 126 | 0.08 | 0.05 | 434