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ILLINOIS ACADEMY OF SCIENCE 



anatis (Schr.). In this species the proboscis of the male 

 and of very young females is of an ordinary type with 

 rows of hooks extending from the extremity to near the 

 base (fig. 5). In contrast with this the proboscis of the 

 female is an inflated spherical organ which bears a star- 

 like cro\Am of hooks (fig. 6), limited in distribution to 

 the anterior face of the structure. 



Filicollis anatis (Schrank) 



Fig. 5. Proboscis of male magnified about 120 diameters. 

 Liihe 1911, fig. 44. 



Fig. 6. Proboscis of female magnified about 30 diameters, 

 fied from Liihe 1911, fig. 39. 



From 



Modi- 



Cuticular spines appear on the body proper of species 

 belonging to certain genera of Acanthocephala. These 

 spines display dimorphism in some instances through dis- 

 similarity in size and in others through difference in dis- 

 tribution. In one species of Ehadinorhynchus the body 

 spines of the female range from 60 to 70/x in length 

 while those from the same region of the male are only 

 about 28/* long. In this instance the female shows 

 greater size of spines in just the same manner as greater 

 body size is associated with the females in the Acantho- 

 cephala. On the other hand the writer has described two 



