296 
Psyche 
[December 
23 24 
Figs. 21-24. Internal genitalia. Cleared dorsal view of epigyna. 21. 
Latrodectus No. 1. 22. Latrodectus No. 2. 23. Latrodecfus No. 3. 24. Latro- 
dectus No. 4. All figures are drawn to the same magnification. 
quarter turns. Although No. 4 appears to have the most convoluted 
duct system } it would be necessary to examine more specimens before 
I could suggest that the quarter turn is signficant. Unfortunately, 
Abalos and Baez limited their characterization of the internal geni- 
talia of Nos. 2, 3 and 4 to a single illustration (p. 63) which rep- 
resents the duct system found in all three populations. 
Measurements . A series of 34 measurements were made on a variety 
of external parameters on 94 specimens (30 specimens from popula- 
tions Nos. 1, 2, and 3; and four specimens from No. 4). After an 
analysis of all the values for each of the populations, the measurements 
from some parameters were discarded because they failed to yield 
normal distributions, e.g., values for the epigynal width yielded a 
bimodal distribution for population No. 3. Values for the sternum 
width produced a distribution which closely approximated a normal 
curve. Two ratios were made with the values of the sternum width 
and two other measurements which were selected at random from 
the list of remaining measurements. A third ratio was made by pairing 
the values of two parameters selected at random. Modified Dice- 
Leraas diagrams for the ratios (Femurl/Sternum width, Metatar- 
