ANGUILI.ULiE. 571 



far than that of which the Lamina? of the cyst are formed. 

 This granular matter is prolonged beyond the mass of 

 Uchhiococci into a short pedicle, common to the whole, and 

 by which the grannlation is attached to the interior of the 

 hydatid cyst, as represented in Ko. 101. In specimens 

 preserved in spirits, Echinococci of all imaginable forms and 

 appearances are to be met with, — dilierences owing to de- 

 composition or to mechanical injury ; and in many cases 

 no traces of them can be found except the booklets or 

 spines, "which, like the fossil remains of animals in 

 geology, remain as certain indications of their source, and 

 not unfrequently afford the only proof we can obtain of 

 the true nature of the hydatid."^ 



The Echinorhynclii, or Acantho cepliali, constitute a 

 group of entozoa, with respect to whose development and 

 life-history we are indebted to Prof. Leu ck art of Giessen. 

 Most observers, and in particular Yon Beneden and G. 

 "Wagner, have been disposed to assign to the Echinorhynd 

 a simple metamorphosis, hardly perhaps more remarkable 

 than that which has been shown to take place in some 

 other of the IlTematode worms. The latter observer goes 

 so far even as to believe that the organization of the per- 

 fect animal may be discerned in the embryo. Leuckart 

 instituted, in 1861, a series of experiments with the ova 

 of Echinorhynchiis Proteus, which is found parasitic upon 

 the Gammarus Pidex. The ova " of E. Proteus resemble 

 in form and structure those of the allied species. They 

 are of a fusiform shape, surrounded wdth two mem- 

 branes, an external, of a more albuminous nature, and an 

 internal, chitinous one. When the eggs have reached the 

 intestine, the outer of these membranes is lost, being in 

 fact digested ; whilst the inner envelope remains until 

 ruptured by the embryo."^ 



Anguillidce are very small eel-like worms, of which one 

 species,^ Anguillula Jluviatilis, is found in rain- water 

 amongst Confervce and Desmidiacece, in wet moss and 

 moist earth, and sometimes in the alimentary canal of the 



(1) Microscopical Society's Transactions. 1st Series. 



(2) Prof. Leuckart "On Echinorhynchiis." Journ. Micro. Soc. vol. iii. p. 57. 1863. 



(3) For the fullest infonnation of marine, land, and fresh-water species, con- 

 sult Dr. Bastian's "Monogi-aph on the Anj,'uillulidse." Liyi. Soc. Trans, vol. 

 XXV. p. 75. The "AngiiiUula Aceti." — Foj^ular S$ietice Review, January, 1S63. 



