116 



THE FUR SEALS OF THE PEIBILOF ISLANDS. 



The adult females vary in length from 25 to 75""", with a diameter of 1 to 2""". 

 The body is attenuated more toward the head than toward the tail. The vulva is 

 found in the middle third of the body, generally near the middle; in a specimen 65™™ 

 long it was 27™™ from the anterior extremity. In the same specimen the vagina 



M 



measures 5™™ long, the body of the uterus 12™"", the horns of the uterus 18™", The 

 eggs are spherical, 48 to 56 ju in diameter, and reach the morula stage in the uterus. 

 Immature stage. — Among the nematodes taken from the stomach of seals are to 

 be found a number of smaller worms, which upon closer examination proved to be 

 young specimens of Ascaris. Similar worms were found also in Leidy's collection 



Fig. 16. 



Fig. 17. 



in association with A. typica. These parasites agree in a general way with the 

 descriptions given of A. oapsularia, and we have no hesitation in considering them 

 the immature stage of the adult worms with which they are associated. This is by 

 no means intended to imply that all specimens recorded by various authors as 

 "J., cwpsularia " are the young forms of A. decipiens or A. typica. On the contrary, 



