THE PARASITIC WORMS COLLECTED BY LUCAS IN BERING SEA. 103 



The tapeworms are fouud iu the large intestine, in the majority of cases with the head fastened 

 in or near to the caecum, which, in the fur seal, is short. 



No tapeworms were found in the two old males killed in August, which had uot eaten for at least 

 two months. 



The worms collected by Lucas came from the fur seal ( (Jallorhinus ursinus), the 

 sea lion {Uumetopias stelleri) and the hair seal (Phoca larghaFalla,s). 



. A species of tapeworin {Bothriocephalus, see p. 168) was found in Gallorhinus; a 

 few strongyles ( Uncinaria, see p. 165) were present in the intestine of a Gallorhinus 

 pup, and ascarides (Ascaris) were present iu Gallorhinus, Eumetopias, and Phoca. 

 T^e ascarides alone were present in large numbers. As it is evidently these worms to 

 which the British referred in the Paris report, and as these were the only worms 

 present in sufficient numbers in 1896 to come into consideration from a medical point 

 of view, furthermore as the time at our disposal for this report is exceedingly limited, 

 almost the entire time allotted for study of the seal parasites has been given to study- 

 ing the members of this genus. 



II.— Family ASCARIDAE. 



This family of round worms is variously diagnosed by different authors, but it 

 must be subjected to a rigid and critical study, with modern methods, before we can 

 tell with any degree of satisfaction which genera should be included iu it and which 

 should be eliminated from it. For generic diagnoses of the forms which come into 

 question, Dujardin (1845), Diesing (1860), and Schneider (1866) especially should be 

 consulted. 



ISTo attempt will be made in this report to define these various genera, as only 

 one of them, the type of the family, comes into consideration in connection with the 

 parasites of seals. It may, however, be remarked that the genus Gonocephalus and 

 probably also Peritraehelius fall as synonyms of Jiscam. 



ASCARIS Linnaeus, 17S8. 



' 1758. Aaearis Liknaeus, Systema naturae, 10th. ed., p. 648. Type by elimination, A. lumbricoides Lin- 

 naeus, 1758. 

 1800. Capsularia Zedbr, Erster Nachtrag Naturg. Eingeweidew., pp. xl, 5, 7. Encysted larvae in 



Salmo and Clupea. 

 1800. ^itsaria Zbder, Erster Nachtrag Naturg. Eingeweidew., pp. xl, 6, 16. ^scoHs renamed and 



including A. lutribricoides, hence type, A. lumbricoides. 

 1845. Ascaris (Ascaris) Dujakdin, Hist. nat. Helminthes, p. 154. Includes type of genus, hence type, 



A. Iwnbricoides. 

 1845. Ascaris (Anisakis) Dujardin, Hist. nat. Helminthes, p. 20. Type, "A. simplex Rudolphi," misde- 



termined=:^. Dussumierii. 

 1860. Gonocephalus Diesing, Sitzungsher. k. Akad. Wiss. Wien, XLII, no. 28, p. 669. Type, Cono- 

 ceplialus typicus Diesing, 1860. 

 Diagnosis. — Body more or less elastic, elongate, cylindrical, more or less attenuated toward both 

 extremities. Mouth anterior, terminal, with three terminal convergent lips, two of which are ven- 

 tro-lateral, the third dorao-median; armed pharyngeal bulb absent. Anus near posterior extremity. 

 Sexes separate. 



Male: With two spicules, ventral caudal papillae present; praeanal sucker absent. 

 Female: Vulva in anterior two-thirds of body. 

 Type : Ascaris lumbricoides Linnaeus, 1758. 



1 No pretensions to a complete generic synonymy are here made. Only such genera and sub- 

 genera are cited which have a direct bearing upon the type species and those species considered in 

 this paper. A complete revision of the nematodes must be made to establish complete generic 

 synonymy. 



