PLATE XXVI * : 
Fig. 24. Neoechinorhynchus crassus, n. sp., from intestine of Catostomus 
commersonii. Optical section of mature male, showing arrangement of internal 
organs and relative thickness of body-wall. Hematoxylin-stained whole-mount in 
damar. P 
Fig. 25. Surface view of proboscis of same individual. 
Fig. 26. Octospinifer macilentus, n.sp., from intestine of Catostomus com- 
mersonii. Optical section of mature male. From hematoxylin-stained whole- 
mount in damar. 
Fig. 27. Surface view of proboscis of same individual. 
Fig. 28. Neoechinorhynchus crassus. Embryo from body-cavity of gravid 
female. 
Fig. 29. Octospinifer macilentus. Embryo from body-cavity of gravid female. 
* Scales indicating magnification of Fig. 24-26 have a value of 1 mm.; all others 
inethe plate have a value of 0.05 mm. 
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