76 
W.F. Ponder, D.J. Colgan, T. Terzis, S.A. Clark, A.C. Miller 
cg 
ppc 
D 
Figure 20. Female reproductive system and stomach of Fluvidona centralia. A,B. Oviducts of two paratypes viewed 
from the left side, showing variation in coiling pattern of coiled oviduct and relative length of albumen gland. 
C. Detail of bursa copulatrix, seminal receptacle and associated ducts from left side. D. Stomach from left 
side (see Figure 8 for labels). ag — albumen gland, bc — bursa copulatrix, cd — common duct, cg — capsule 
gland, co — coiled oviduct, po — pallial opening of oviduct, ppc - posterior pallial wall, sr — seminal 
receptacle, vc — ventral channel. Scales 0.25mm. 
Shell length 
A 
T 
* 
"t 
жо 
based ЧЕНИ) 1 =p. 
ip) {ж ЕЗ FQ Gal Ga3A 
Spring 
Aperture length/shell length 
0.52 
047 + 
042 rt 
0.32 í = 1 ! 
0.50 054 0.58 062 066 070 
В Shell width/length 
Figure 21. A. Box plots showing variation in shell length of Fluvidona centralia (For an explanation of box plots see 
Figure 16). B. Separation of the two electrophoretically distinct groups within F. centralia using two shell 
ratios. Samples from springs Cd11, El and F9 are represented by circles, those from springs E3 and Gal by 
diamonds. The ellipse represents 75% of the variance. 
