HETEROTRICHA 



549 



Genus Nyctotherus Leidy, 1849. 



Definition. — -Body bean- or kidney-shaped, with a large peristome 

 on the concave side extending from the anterior end up to the middle 

 of the body, from where a curved cytopharynx or oesophagus extends 

 inwards. The macronucleus is large, and situated almost in the 

 cen' re. 



Remarks. — The species are mostly parasitic in the intestine of 

 Amphibia, Insecta, and Myriapoda. 



Species known in man: Nyctotherus faba vSchaudinn. 1S99; 

 N. giganteus Krause, 1906; A^. africanus Castellani, 1905. 



Nyctotherus faba Schaudinn, 1899. 



N. faba is flattened dorso-ventrally, and is 26 to 28 /j, in length, 

 and 16 to 18 /bt in breadth, and 12 ^ in thickness. The cilia on the 

 peristome are of two kinds, those 

 on the right side, of the size of 

 the body, being true cilia, and 

 those on the left side being cirri. 



Fig. 202. — ■Nyctothenis faba 

 Schaudinn. 



(After Hartmann. From the Archiv 

 filr Schijfs- u. Tropenhygiene.) 



The contractile vacuole is large, and situated posteriorly. The 

 macro-nucleus is in the centre, and is peculiar in having four or 

 five large collections of chromatin at its periphery. The micro- 

 ' nucleus lies close by. The cysts arc oval. 



This species was discovered by Schaudinn in the same patient 



Balantidium minutum. 



Nyctotherus gig?.nteus P. Krause, 1906. 



Synonym,— Balantidium gigantetim P. Krause, 1906. 



This organism, along with Trichomonas intestinalis, was found by 

 Krause in the dejecta 'of persons suffering from typhoid in Breslau. 



It is shaped like a truncated cone, with the anterior end narrowed, 

 and the posterior broad. Lengta, 90 to 400 breadth, 60 to 150 fj,. 

 Surface covered with cilia. The peristome is situated laterally, 

 and from it a cytopharynx leads inwards. 



Fig. 203. — Nyctotherus africanus 

 Castellani. 



