244 ORDER FLAGELLATA-PANTOSTOMATA. 



This species was found by Biitschli in considerable quantities in the intestinal 

 tract of the above-named host ; some freely detached, and others united to one 

 another in clusters by their posterior extremities. Their movements when liberated 

 into the surrounding water, were swift and vigorous. 



GENUS V. OPHIDOMONAS, Ehr. 



Animalcules free-swimming, very elongate, thread-like or vermicular, 

 persistent in shape but more or less spirally curved ; a single flagellum at 

 the anterior extremity ; parenchyma usually enclosing numerous refringent 

 corpuscles. 



The single species referred to this genus by Ehrenberg in his ' Infusionsthiere,' 

 under the title of Ophidomonas jenensis, but without any accompanying illustration, 

 was represented as a loricated animalcule. In a more recent publication, however,* 

 he gives an illustration of both this and a second presumed form of the same genus, 

 O. sanguinca, which by no means supports such an interpretation. The close 

 correspondence in general contour of the members of this genus with those of 

 Vibrio or Spirillum is at first sight very striking ; the larger size and presence of 

 a flagellum at the anterior extremity only of the thread-like body in the case of 

 C. jenensis, afford, nevertheless, substantial marks of distinction. The motions 

 of these organisms in the living state are furthermore entirely distinct from those 

 of Spirillum and its allies, the body being drawn through the water after the manner 

 of the ordinary Flagellata by the vibrations of the single anterior flagellum, while 

 with the Spirilla the posterior flagellum represents the organs of locomotion, and 

 propels the body in advance. The existence of an endoplastic or contractile vesicular 

 system remains to be demonstrated, as also whether or not solid food-particles can 

 be ingested. 



Ophidomonas jenensis, Ehr. PL. XIII. FIGS. 27 AND 28. 



Body elongate, vermicular, obtusely rounded at each extremity, more 

 or less spirally twisted ; about one-twelfth as broad as long ; flagellum 

 undulating, nearly equalling one-half of the body in length ; colour olive- 

 brown, enclosing one or more rows of clear refringent corpuscles. Length 

 1-570". HAB. Spring water. Increasing by transverse fission. 



Ophidomonas sanguinea, Ehr. 



Body very long, slender, and flexible ; about twenty-four times as long 

 as broad ; parenchyma usually transparent, and enclosing minute brilliant 

 crimson corpuscles, sometimes suffused with a paler tint of the same colour. 

 Length 1-570". HAB. Pond and brackish water. 



Although reported by Ehrenberg as an inhabitant of brackish water, examples 

 according in all essential points with the type of this species, as figured by that 

 authority, have been obtained by the author in pond water. Such personal acquaint- 

 ance with it has, however, given rise to the opinion that this organism is in no 

 way related to the preceding form, but represents rather the filamentous con- 

 dition of a Spirillum closely, if not absolutely, identical with the organism figured and 

 described by Messrs. P. Geddes and J. Ewart in the ' Proceedings of the Royal 

 Society,' p. 482, pi. xi. fig. 4, 1878. No flagellate appendages could be discovered 

 with the comparatively low magnifying power then at disposal, and its movements 



' Abhandl. Berlin Akad.,' 1862. 



