176 THE FUR SEALS OF THE PRIBILOF ISLANDS. 



Fig. 44. Oesophagus of Ascaris lypkii fioiu U.S.N.M., No. 5015, divided into an anterior straight portion 



and a posterior sigmoid portion. Intestinal and oesophageal caeca are absent. Zeiss 



4/a*io. Original. 

 Fig. 45. Lateral view of tail of male oi Ascaris typica from IT.S.N.M., No. 5015, to show the structures 



described in the text. Zeiss 4/16, stage. Original. 

 Figs. 4t>-47. Ventral view of the tails of two male specimens of Ascaris simplex from U.S.N.M., No. 



5015, showing the unequal spicules and variations in the position of the caudal papillae. 



Zeiss 4/16, stage. Original. 

 Fig. 48. Eggs o{ Ascaris simplex from U.S.N.M., No. 5015, in various stages of segmentation. Zeiss 



4/4, stage. Original. 

 Fig. 49. A young specimen of Ascaris typica from U.S.N.M., No. 5015, partially surrounded by its larval 



cuticle. Zeiss 4/a* 111. 

 Fig. .50. Anterior extremity of a young specimen of Ascaris typica which has cast pait of its larval 



cuticlt!. Zeiss 4/8, stage. Original. 

 B'ig. 51. Caudal extremity of a young specimen of Ascaris typica before the larval cuticle has been 



cast. Zeiss 4/8, stage. Original. 

 Figs. 52-56 are given in text. 

 Fig. 57. Dorsal lip of Ascaris patagonica, showing the double dontigerous ridge antl other structures 



given in the diagnosis. After von Linstow, 1880, j)!. lii, fig. 1. 

 Fig. 58. Male of Ascaris Kiikenthalii. Natural size. After Cobb, 1888, pi. in, lig. 1. 

 I'ig. 59. Male of Ascaris Kiikenthalii, opened on the left side to show the anatomy: !>., bulbus of the 



oesophagus; de., "end portion of the intestine" (or ductus ejacnlatorius?) ; e<l-, rectum; 



eo., excretory organ; h., testicle; kmd., smaller jjortion of the intestine; I., glandular 



organ; vi., mouth; mh., bursal muscles; md., intestine; ms})., muscles of a spicule; 



oe. , oesophagus ; si., vas deferens; sp., spicules; »»., vcsicula semiualis ("Saineuschlauch"). 



After Cobb, 1888, pi. in, fig. 7. 

 Fig. 60. Tail of niah^ of Ascaris Kiikenthalii, opened ventrally to show the anatomy: a., anus; 



de., ductus ejaculatorius; dim., dorsal longitudinal muscle; ed., rectum; h., testicle; 



mh., bursal muscle; «/., lateral line; sfb., broadened portion of lateral line; s/., vas 



deferens; sp., spicules; »«., vesicula seminalis (" Samenschlauch"). x 2. After Cobb, 



1888, pi. HI, fig. 5. 

 Fig. 61. Ventral view of tail of male of Ascaris Kiikenlhalii, showing the cloaca and caudal papillae as 



as seen by Cobb. After Cobb, 1888, ])!. iii, fig. 3. 

 Fig. 62. Apex view of head, showing the position of the lips: jje, excretory pore, x 50. After Cobb, 



1888, pi. Ill, fig. 11. 

 Fig. 63. Female specimen of Ascaris Kiikenthalii. Natural size. After Cobb, 1888, pi. ill, fig. 2. 

 Fig. 64. Anterior extremity of Ascaris Kiikenthalii, opened ventrally to show the anatomy: a;/., termi- 

 nal duct of excretory organ; eo., excretory organ; esf., constriction of lateral field; 



geo., duct of excretory organ; m., mouth; wirf., intestine; iir., neural ring; om., muscle; 



rn., dorsal nerve; sf., lateral line, x 2. After Cobb, 1888, pi. iii, fig. 4. 

 Fig. 65. Ascaris similis, natural size, after Baird, 1853, pi. I, fig. la. Baird states that this is a male, 



but it is more probably a female. 

 Fig. 66. Head of male, magnified, showing three lips; intermediate lips arc; absent. After Haird, 



1853, pi. I, fig. Id. After Baird, 18.53, pi. i, fig. lb. 

 Fig. 67. Ascaris .Himilis, natural size, after Baird, 1853, pi. i, fig. Ic. Baird states that this is a female, 



but it is more probably a male. 

 Fig. 68. Head of female, magnified, after Baird, 18.53, pi. i, fig. Id. 

 Fig. 69. Tail of female, magnified, after Baird, 1853, pi. I, fig. le. 

 Fig. 70. Ascaris halicoris, after Baird, 1859, pi. i.vi, fig. 2. 

 Fig. 71. Head of Ascaris halicoris, showing the three lips; intermediate lips are absent. After Baird, 



18.59, pi. i.vi, fig. 2a. 

 Fig. 72. Tail of Ascaris halicoris, after Baird, 1859, pi. LVi, fig. 2b. 

 Fig. 73. Anterior portion of Ascaris halicoris, dissected to show the oesophagus, intestine, intestinal 



caecum, and a portion of the genital organs. After Baird, 1859, pi. LVi, fig 2c. 

 Fig. 74. Transverse section of head of Ascaris halicoris, showing the relative position of the three lips 



and the absence of intermediate lips. After Parona, 1889, pi. xiii, fig. 3. 



