XU CONTENTS. 



OHAPTBE IV.— Nematoda. 



The order of round worms, or Nematoda— Aspect, habits, and distribution— Probable 

 number of known species— Classification— AnguillulidEe— The common viaegar eel 

 as a type— Genera— Gordiidee, or family of hair-worms— Dujardin's account of the 

 structure of Mermis nigrescens— The views of Meissner, Von Siebold, and Van Be- 

 neden respecting the development of Mermis— Genera— Structure of Sphaerularia — 

 Oxyuridse, or thread-worms — Organization of Oxyuris eurvula—Orenera. . P. 52 — 67 



OHAPTBE v.— Nematoda. 



The Filaxidse — Triohoeephalus affinis considered as a type — "Wilson's investigations 

 respecting its anatomical structure — The views of Kuchenmeister and of Eberth 

 regarding the characters presented by the reproductive organs, compared with 

 those severally entertained by Mayer, Eberth, and the Author— Embryonic develop- 

 ment — Genera — Simondsia paradoxa — Oheiraoanthidse — Genera — ^AscaxidEe — Genera. 



68—82 



OHAPTBE VI.— K"bmatoda. 



StrongylidsB — Genera — The Sderostoma syngamus as a type, with a particular account 

 of the gape disease which it occasions— Structure and development — Remedial 

 methods — The genus Prosfhecosacter—Ovgasnz&iiioTL of Prosthecosacter convolutus — 

 Mode of reproduction — Oucullanidse — Genera 83 — 96 



OHAPTBE VII.— Acahthocephala. 



Acanthocephala or Thorn-headed worms — General characters and distribution — Olassi- 

 fioation — Organization of Echinorhynchus anihwis. Singular mode of egg-forma- 

 tion— Leuckart's researches respecting the development oi Echinorhynchus proteus — 

 His discovery of the so-called phenomenon of " alternate generation" in this 

 class of parasites 97 — 103 



OHAPTBE VIII.— Oestoda. 



Oestoda or Tapeworms — General characters and habits — Distribution in mammals, birds, 

 reptiles, and fishes — Estimated number of species — Tffiniadse — Particular account of 

 the development of Cysticercus pisiformis from the eggs of Tcenia serrata, and also 

 of the adult tapeworm from the Oysticercus — Constitution of the " zoological indi- 

 vidual" — Genera . . . . . . ... 104 — 115 



