DESCRIPTIONS OF GENERA AND SPECIES 



635 



three of the species of Anteusj in A. appuni there are roughly the same number 

 of segments devoid of setae as in TyJconus, though the lateral commence before the 

 ventral setae; the reverse, however, is the case with A. callichaetus, and the setae 

 are not deficient on so great a number of segments. It does not, therefore, appear 

 possible to separate Tykonus, unless we include in it 'Anteus' appuni. 



I am of opinion that this character, which serves also in part to distinguish the 

 New-World Geoscolicids, Rhinodrilus and Onychochaeta, and the Old-World Micro- 

 chaeta, Kynotus, may be used also to distinguish Tykonus from its near alUes. It 

 wiU be noted from the above table that the two species which I propose to include 

 within this genus Tykonus agree, furthermore, in having but a single pair of sperm- 

 sacs; it maj' be that they have also but a single pair of testes, as the one character 

 often goes with the other (e.g. Pontoscolex and Typhaeus). Of less importance is 

 the fact that no one of the three species has more than two pairs of calciferous 

 glands and spermathecae (? as to Tykonus grandis in respect of the latter character). 



'Anteus' papillifer resembles Urobenus brasiliensis in having intestinal caeca in 

 the twenty-sixth segment. This singular point of likeness to Perichaeta is to my 

 mind a character worthy of being regarded as generic. The slight deficiency of setae 



in the first named species (not found in Urobenus brasiliensis) cannot be compared 

 to the great deficiency of setae in Tykonus^- These two species, moreover, appear 

 to agree on the whole in the characters of the sperm-sacs. 



Finally, I would not leave Anteus brunneus in the genus to which Michaelsen 

 has referred it, but assign it to Rhinodrilus, where also I place A. callichaetus, on 

 account of its modified copulatory setae and glands, which seem also to occur in. 

 R. tenkatei. 



'■ Cf., however, the different species of Kynotus and Microchaeta. 

 4 M a 



