524 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
caecilians separated themselves from their enveloping membranes 
and crawled about in a dry pan. They probably would have been 
born the same or the next day. 
The eye spot is visible in all specimens. Measurements are as 
follows: 
4 Rings |Complete| Total Diam- 
U.S.N.M. No. Prima- | without anal acai eter 
ries | second. | Seammde | Jength | amy | Wd 
1 Ras Ua esa FAUT lS 121 23 15 280 7 40 
PEE O59: cue Bal CnC LT ANSE UNL PAR es a Neen AAI 120 16 48 99 4 24. 75 
A) B11 6E YAR RE ML ee a UU ANIA ee 119 15 41 98 4 24.5 
PO OG Ye TOL eh A ee Ua Be 122 24 21 98 4 24.5 
TISOG 2a nO Rae ay NU RNY Rat Sao Dao 119 17 20 96 4 24 
SD Da Oy foe ACN ea eI ye CN aL 135 13 10 151 4,5 33. 6 
The primary rings are less numerous in Chiapas specimens than in 
most from Oaxaca and Guerrero. Recorded counts from seven 
Chiapas caecilians show a range of variation from 119 to 122; in 12 
Guerrero and Oaxaca individuals the range of variation is from 124 to 
135, with the exception of one specimen, which has 121. 
It is extraordinary that the number of complete secondaries should 
be so greatly increased over the normal complement of adults and sub- 
adults in the newly born young. ‘The maximum known in adults is 16, 
while all the four young have over 19, and two have over 40. It ap- 
pears that the number of complete secondaries decreases shortly after 
birth, and not impossibly over a longer period. If such is the case it 
might be expected that the number of incomplete secondaries should 
be increased in the young, over the normal number in adults, and thus 
result in the presence of fewer spaces between primary rings lacking 
secondary rings, but this does not occur. 
The foregoing table suggests that an increase in the 1/d ratio may 
be correlated with the increase in age (length). That this 1s not so is 
indicated by Dunn’s table (1942, p. 469), in which large specimens 
with 1/d ratios both small (26, at 390 mm. length) and large (39, at 275 
mm. length) occur in the Oaxaca-Guerrero area. Another possibility 
suggested, however, is that females have slenderer bodies than males; 
specimens with ratios from 24 to 29 may be males, those with 33 to 4C 
females (intermediate ratios are not recorded). The slenderest 
specimen recorded is one that had just given birth to its young; very 
probably it represents an exaggerated condition, yet it appeared but 
very little more robust just before giving birth to its young. A 
nearly equally slender condition (88, 39) is reached in other speci- 
mens collected in August, long after the season when the young are 
born. 
