72 EARTHWORMS AND THEIR ALLIES [ch. 



These genera are Onychochaeta with one species, 

 Hesperoscolex of which one species is known from 

 the area, Periscolex with one species, Anteoides with 

 two species, Pontoscolex one species. Opisthodrilus 

 with two species, RMnodrilus (including either as 

 synonyms or as sub-genera, Thamnodrilus, Anteus, 

 Tyhowus, Uroberms and Aptodrilus) with no less 

 than 49 species : Andiodrilus with five species, 

 Holoscolex with one species, Glossoscolex ten species, 

 Fimoscolex, Andiorrhinus and Enantiodrilus with 

 one species apiece. 



Thus of this sub-family of Geoscolecidae we have 

 in South America a large number of genera and a 

 much larger number of species. Of a second sub- 

 family of Geoscolecidae there are three species of 

 Criodrilns found in the South American Continent. 



We now turn to the Megascolecidae of which a 

 large number of species occur within the area now 

 under consideration. The bulk of these belong to 

 the sub-family Acanthodrilinae and they are as 

 follows : 



Of the genus Notiodrilus there are ten species, 

 of Microscolex two species, of Chllota 19, of Yagan- 

 sia 13. 



A second sub-family Trigastrinae also occurs in 

 this Continent and the following genera are permanent 

 inhabitants, viz. : 



Dichogaster(=Benliamia) with only three species, 



