■ GENUS OPHRYOSCOLEX—ENTODINIUM. 653 



animalcules in health for a considerable interval — nine hours or more — by placing 

 them in glass tubes containing the stomachal fluids of their host, maintained at a 

 temperature of from 30° to 35° centigrade. 



The present author provisionally refers to this family group the Astylozoon 

 fallax of T. W. Engelmann, which, while included by Stein among the ordinary 

 Vorticellidje, appears to exhibit in its free-swimming condition, and possession of 

 stylate caudal appendages, a closer relationship to the t\vo genera above named. 

 The trend of the adoral wreath and the assumed position of the anal aperture may 

 perhaps be deemed of sufficient import for their isolation, but as in either case 

 the animalcules have been examined by no means exhaustively, and by but one 

 obsen-er, their provisional alliance appears desirable. 



Genus I. OPHRYOSCOLEX, Stein. 



Animalcules free-swimming, ovate or elongate, cuticular surface densely 

 indurated or encuirassed ; oral aperture anteriorly situated, associated with 

 an extensile and retractile peristome ; ciliary wreath like that of Vorticella, 

 except that the left limb, instead of the right, descends into the oral fossa ; 

 the centre of the body half encircled dorsally by an arcuate row of stout 

 uncinate cilia or setae ; a long, stylate, tail-like appendage produced back- 

 wards from the post-ventral surface, the anal aperture situated close to 

 the base of this style ; endoplast conspicuous ; contractile vesicles usually 

 multiple. Hab. — Endoparasitic. 



Ophryoscolex Purkynjei, Stein. 



Body elongate, somewhat vermicular, rounded posteriorly, bearing in 

 addition to the tail-like style three short, cur\'ed, claw-like spines ; the 

 anterior margin truncate, closing in a sphincter-like manner over the peri- 

 stome when retracted ; the ventral surface flattened, the dorsal and lateral 

 ones convex ; endoplast elongate-ovate, having a round attached endo- 

 plastule, situated on the right side of the body ; contractile vesicles two or 

 three in number, spherical. Dimensions unrecorded. 



Hab. — Endoparasitic, within the first and second stomachs of sheep and 

 cattle. 



Ophryoscolex inermis, Stein. 



This species corresponds with O. Purkynjei, but is devoid of the short, 

 claw-like spines at the posterior extremity ; increase by transverse fission 

 has been observed in this, but not in the last-named type. 



Hab. — Identical with that of O. Purkynjei. 



Genus H. ENTODINIUM, Stein. 



Animalcules free-swimming, ovate, more or less flattened ; cuticular 

 surface smooth and densely indurated ; oral aperture and peristome as in 

 Ophryoscolex ; anal aperture postero-terminal ; no central girdle of setose 

 cilia, often with one or more terminal spines ; endoplast band-like, having 



