164 , THE PUE SEALS OF THE PRIBILOP ISLANDS. 



As Steller's sea cow is now extinct it can never be demonstrated what species 

 Steller found. The names A. rytinae and A. rhytinae may, therefore, be buried, and 

 all time used in speculating as to the affinities of this worm with corresponding para- 

 sites in other hosts may be considered lost. 



14. "ASCARIS CAPSULARIA." 



Ascairis capsularia is a name applied to immature nematodes, supposed to be 

 ascarides, and found in fish. Numerous supposed species have been separated under 

 distinct specific names, generally taken from the names of the hosts, the generic names 

 Agamonema, Hfematoideum, or Ascaris being used by various authors. Personally, we 

 must confess our inability to distinguish at present these numerous forms from each 

 other or to determine from the published descriptions of the worms which forms should 

 be considered synonyms, which forms should be looked upon as distinct, and which 

 forms should be associated with this, that, or the other adult Ascaris. We do not deny 

 that other authors are correct in their interpretations of these larval worms, but we 

 would suggest that a thorough study of the exact food habits of fish-eating mammals 

 in connection with this subject would aid in solving the problem of the life history of 

 many of these parasites. 



III.— Family STRONGYIIDAE. 



Diagnosis. — Nematoda with body elongate, cylindrical, rarely filiform. .Mouth is probably 

 always provided with six papillae, of which the four submedian are generally salient iu form of nodules 

 or conical points. In some cases the mouth is in the axis of the body; in others, turned dorsally or 

 ventrally, and occasionally provided with a chitinous armature. Oesophagus more or less swollen in 

 posterior portion, but without forming a. distinct oesophageal bulb. Males provided with a caudal 

 bursa, open or closed, entire or divided, with one or two spicules. Females with one or two ovaries; 

 vulva anterior or posterior to middle, iu some cases near the anus. Eggs deposited during segmenta- 

 tion, in some cases containing embryo. 



Type: Strongylus, 0. F. Miiller. 



SiiTafamily SOLBROSTOMIN".!^K. 



Diagnosis. — Strongylidae; meromyaria; mouth with more or less complete chitinous armature. 

 Male with two equal spicules ; caudal bursa with rays, the postero-median and postero-external being 

 united in a common base. Female with two ovaries, except in Ollulanua. 

 Type: Sclerostoma, Blainville, 1828. 



Genus UNCINARIA Frolieh, 1789. 



1789, Uncinaria FkOlich, Der Naturforscher, XXIV, pp. 137-139. Type, Vndnaria vulpis Frolioh, 1789. 

 lS43,Agchyloatoma Dubini, Annal. univers. di medic. Milano, CVI, April, pp. 5-13. Type, Agchylos- 



toma duodenale Dubini, 1843. 

 1845, Ancylostoma Crbplin, Archiv. f. Naturg., 11 Jhg., I, p. 325. For Agchylostoma Dubini, 1843. 

 1845, Dochmiua Dtjjardin, Histoire naturelle d. helminthes, pp. 267-275. Type, Dochmius tngonoeej>h'- 



aVaa (Rudolphi, 1809) = Uncinaria vulpis Frolieh, 1789. 

 (1846), Anchyloatoma Dbllb Chiajk Rendioon. dell Accad. delle Sci. Napoli, V, p. 339. 

 1851, Anchyloatomum Diesing, Systema helminthum, II, p. 321-322. For Agchylostoma Dubini, 1843. 

 1855, Ancyloatomum Kf5cHENMEiSTER, Die iu und auf d. Korper d. lebenden Mensohen vorkommend. 



Parasiten, I, p. 297. 

 1861, Monodontua Molin [nee Monodonta Lamarck, 1799], II Sottordine degli Acrofalli, pp. 11-43. 



Type, M. semidrcularis Molin, 1861. 



Diagnosis.— Sclerestominae with anterior extremity curved dorsally ; month round to oval, open- 

 ing obliquely, limited by a transparent border and followed by a chitinous buccal capsule ; the dorsal 

 portion of "the capsule is shorter than the ventral, and is supported by a conical structure the point 

 of which sometimes extends into the cavity: ventral at the base of the buccal capsule are found two 



