216 ILLINOIS BIOLOGICAL MONOGRAPHS [504 



EXPLANATION OF PLATE 



Fig. 45. Bothrimonus intermedius, scolex and anterior end, toto preparation, showing fore- 

 most sets of genitalia. 



Fig. 46. Marsipometra hastata, plerocercoid, siirficial view. 



Fig. 47. Marsipometra hastata, older plerocercoid, surficial view. 



Fig. 48. Clestobothrium crassiceps, toto of scolex and anterior end. 



Fig. 49. Clestobothrium crassiceps, toto of young strobila, surficial vi ew. 



Fig. 50. Abothrium crassum, plerocercoid from Cristivomer namaycush, surficial view. 



Fig. 51. Abothrium crassum, same specimen, lateral view. 



Fig. 52. Abothrium crassum, young strobila from same host. 



Fig. 53. Abothrium crassum, older strobila from same host. 



Fig. 54. Abothrium crassum, still older strobila, showing dropping off of segments posteriorly. 



