GENUS CHCENIA. 521 



Enehelyodon, and the entire absence of a separated conical prolongation at the 

 anterior extremity, supply ample grounds for its generic isolation from Lacrymaria. 



Lagynus elegans, Engl. sp. PL. XXVII. FIG. 35. 



Body elastic, flask-shaped, about three times as long as broad, rounded 

 and widest posteriorly, produced anteriorly in a neck-like manner ; oral 

 aperture at the apex of this neck-like portion conducting to a funnel-shaped 

 longitudinally plicate pharynx ; cuticular surface coarsely ciliate, traversed 

 longitudinally by faint, widely separated striations, the more attenuate 

 neck-like portion exhibiting three or four transverse annulations ; con- 

 tractile vesicle single, postero-terminal : endoplast central, ovate, associated 

 with a laterally attached endoplastule. Length 1-150" to 120". 



HAB. Fresh water. 



Conjugation, effected by the close application of the oral surfaces of two indi- 

 vidual zooids, was in one instance observed by Engelmann. 



Lagynus laevis, Quenn. 



The form and proportions of this animalcule, as figured by Quennerstedt, cor- 

 respond closely with those of L. elegans, but the cuticular cilia are much finer, and 

 the narrower, neck-like portion is not interrupted, as in that species, by transverse 

 annulations. 



GENUS VI. CHCENIA, Quennerstedt. 



Animalcules free-swimming, highly elastic, elongate or vermicular ; oral 

 aperture at the anterior extremity, widely dilated during the passage of food- 

 substances, otherwise inconspicuous ; cuticular surface ciliate throughout, 

 a brush-like tuft of larger cilia surrounding the apical or oral extremity. 



Chcenia teres, Duj. sp. PL. XXVII. FIGS. 41-44. 



Body linear-lanceolate or vermicular, highly flexible, ranging, according 

 to degree of extension, from about eight times to as much or more than 

 twenty-three times as long as broad, the posterior extremity obtusely 

 rounded, the anterior one conically pointed ; cuticular surface finely ciliate, 

 faintly striate longitudinally ; oral cilia forming a forward-directed, brush-like 

 tuft, a few slightly longer cilia developed at the posterior extremity ; 

 contractile vesicle single, postero-terminal. Length variable, 1 1 50" to 1 100" 

 when contracted, 1-50" to 1-30" when fully extended. 



HAB. Salt water. 



In describing this type, and instituting a new genus for its reception, Quenner- 

 stedt * confers upon it the title of Chcenia vorax, but at the same time suggests the 

 possibility of its being identical with one of those widely diverse forms, the Enchelys 

 farcimen of Ehrenberg, the Enchelyodon elongates of Claparede and Lachmann, or 

 the Trachelius teres of Dujardin. Having recently encountered this animalcule in 

 sea water at St. Heliers, Jersey, the author is satisfied that Quennerstedt's con- 

 jecture with reference to the last-named species, is correct, and hence the specific 

 name originally given to it by Dujardin is here retained. In the examples personally 



* ' Sveriges Infusoriefauna,' 1867. 

 VOL. II. E 



