THE PARASITIC WORMS COLLECTED BY LUCAS IN BERING SEA. 103 



The tapeworms are fouud ia the large iutestiae, ia the majority of cases witli 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 not eaten for at least 

 two months. 



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

 sea lion {Eumetoi}ias stelleri) aud the hair seal [Fhoca largha Pallas). 



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

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

 pup, and ascarides {Ascaris) were present in Callorhinus, Uumetopias, and Phoca. 

 The 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 in 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. 



No 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 Conocephalus and 

 probably also Feritrachelius fall as synonyms of Ascaris. 



ASCARIS Linnaeus, 1758. 



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

 naeus, 1758. 

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



Salmo and Clupea. 

 1800. jFusaria Zeder, Erster Nachtrag Naturg. Eingeweidew., pp. xl, 6, 16. Ascaris renamed and 



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

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



A. lumbricoides. 

 1845. Ascaris (AnisaMs) Dujardin, Hist. nat. Helminthes, p. 20. Type, "A. simj}lex Rudolphi," luisde- 



termined = ^. Dussumiexii. 

 1860. Conocephalus Diesing, Sitzungstaer. k. Akad. Wisa. Wien, XLII, no. 28, p. 669. Type, Cono- 

 cephalus 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 dorso-median ; armed pharyngeal bulb absent. Anus near posterior extremity. 

 Sexes separate. 



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

 Female : Vulva in anterior two-thirds of body. 

 Type: Ascaris lumbricoides Linnaeus, 1758. 



' 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. 



