ASCARIS DECIPIENS. 



119 



of uematodes has been sucli that we are iucliued to suspend judgiueut iipou them all 

 until the originals have been restudied. (See Ascaris capsularia, p. 164.) 



Source of Infection, — From the facts that ascarides corresponding to the so-called 

 A. capsularia are present in the seal's stomach, and that all intermediate stages 

 between these young forms and the adults are found, it is clear that the seal 

 becomes infected with A. decipiens by eating fish. According to the reports of those 

 who have studied the question, the food of the fur seal consists mainly of surface 

 swimming lislies and of squid. The Alaskan pollock {PoUachius chalcogramnms = 



Fig. 20. 



Theragra chalcogramma)^ a species of red rocktish {Sebastodes), a squid {Gonatus 

 amoenns) are the forms most frequently eaten; salmon and other flsbes are occasion- 

 ally taken. 



Numerous encysted specimens (U. S. jST. M., No. 2821) of "A. capsularia^' were found 

 in a specimen of Pacific cod {Gadus macrocephalus) collected by Lucas in Bering Sea. 

 We have been unable to recognize any dift'erences between these larval worms and 

 the youngest forms found in the stomach of the seal. At the same time we have 

 not been able to distinguish the lips clearly in this form, and on that account it is 



