108 ORGANIZATION OF THE INFUSORIA. 



however, the total limit of infusorial dissemination ; several groups are 

 distinguished for their exclusively endoparasitic habits, the alimentary 

 and circulatory systems of various Vertebrata and Invertebrata, including 

 that of man himself, being often the unconscious entertainers of infusorial 

 guests. As the result of the most recent investigation, one considerable 

 group is found associated with offensively putrid fish and other animal 

 macerations, while in a totally opposite direction, as discovered by the 

 present author, and recorded in the chapter devoted to the subject of 

 Spontaneous Generation, the limpid water of condensed dew or falling 

 rain as it settles on the grass provides a microcosm for the maintenance 

 of a still more extensive series. 



Passing in brief review several of the more abnormal habitats now 

 enumerated or recorded in the succeeding chapters, those infusorial 

 organisms distinguished for their salt-water predilections may be first 

 noticed. Although as yet our knowledge of the marine species of Infusoria 

 may be said to be but imperfect, many generic and family groups may 

 be cited as belonging almost entirely if not exclusively to this category. 

 Commencing with the higher Ciliate division, the free-swimming pelagic 

 forms Tintinnus, Codonella and Dictyocysta, and the sedentary type Follicu- 

 laria, are especially prominent. In the last-named genus, a single fresh- 

 water species, F. Bottom, has, however, been quite recently discovered. Other 

 genera, such as Lembus, Metacystis, and Blepharisma, while essentially 

 marine, are more notably littoral or stagnant sea- water types. To this 

 last-named group have also to be referred the two Hypotrichous family 

 divisions of the Chlamydodontidae and Ervilliidae, and the three separate 

 genera Styloplotes, Uronychia, and Epiclintes. Among the Cilio-Flagellata, the 

 genus Ceratium is almost entirely marine ; C. longicorne and C. kumaonense 

 being the only known fluviatile forms, while the allied genera Prorocentrum, 

 Amphidinium, and Dinophysis are exclusively pelagic. Noctiluca and Lepto- 

 discus may be selected from the Flagellate section as the most conspicuous 

 pelagic types, the several genera, Glyphyidium, A nchonema, and Conchonema, 

 being in a similar manner characteristic of sea-water in its stagnant or 

 putrid state. The section of the Tentaculifera is pretty evenly balanced 

 between salt and fresh water habitats; two genera, OpJiryodendron and 

 Ephelota, are, however, so far as known, exclusively marine. Although 

 the foregoing generic and family groups are here quoted as typically 

 characteristic of the marine infusorial fauna, they are by no means cited as 

 constituting an exhaustive summary. It will be further found that a very 

 considerable percentage of the more ordinary fluviatile types of the Ciliata 

 have likewise their marine representatives, and as familiar examples of 

 which may be mentioned the greater number of genera of the exten- 

 sive family groups of the Vorticellidae, Oxytrichidae, and Euplotidae, not 

 a few species among these, indeed, such as Ophrydium versatile and 

 Uronema marinum, being notable for their indifferent salt and fresh water 

 habitat. 



