INFUSORIA. 53 
Orper IV. Eipitricha. 
Animaleules moving by means of vibratile cilia. 
Section 1. Astoma}. 
Family IX. Pertdinewa. Loricated, with a coronet, or a trans- 
verse belt of cilia. 
Peridinium Eurens. (Species of Cercaria MUELL.) 
Sp. Peridiniwm tripos Enruns. (Cercaria tripos MuEtu., Infus. Tab. xix. 
fig. 22; EnRENB., Infusionsth. Tab. xxtt. fig. Xvi. ; the lorica terminates 
in three points; two anterior curved backwards, and one posterior, 
which is straight. The animacule attains a length of + line ; it is found in 
the Baltic, : 
MIcHAELIS observed a phosphorescence in this and some other species of 
this genus, and thus proved, what had been suspected before, that Infu- 
sories contribute to the illumination of the sea. Ueber das Leuchten der 
Ostsee, Hamburg, 1830; comp. EBRENBERG, Das Leuchten des Meeres. Ein 
in der Konigl. Akademie der Wissenschaften gehaltener Vortrag. Berlin, 
1835, 4to. 
To this genus also probably belong as fossil species some organic 
remains which EHRENBERG discovered in the chalk-formation in fire- 
stones. 
Dinophysis Eurens. (Abhandl. d. Konigl. Akad. d. Wiss. zu 
Berlin, a.d. Jahre 1839, s. 124.) 
Section 1. Stomatoda. (Animalcules with mouth and ceso- 
phagus leading into the parenchyme of the body. One or more 
round, contractile cavities, pulsating rhythmically, situated beneath 
the integument at the surface of the body.) 
Family X.  Trichodina (Trachelina and Colpodea EXHRENB.) 
Body oval, with vibratile cilia, without cirri or styli, not loricated. 
Trichoda Mun.u. (in part, Trichoda Dusarv. and Trachelius 
ScHRANK, Eurens., Dusarp.) An oblique row of large cilia at 
the mouth. 
Phialina Bory, Exrens. 
1 I consider this description as mefely provisional. As to the presence of a mouth 
in particular genera of Infusories much variety of opinion exists, and that the point 
is not easy to determine will be obvious to every one who observes for himself, This 
character, then, in the present state of our knowledge, scarcely deserves 2 prominent 
position. [Vid. note 1, p. 39.] 
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