16 EARTHWORMS AND THEIR ALLIES [oh. 



derived from the important fact that it possesses two 

 gizzards. 



Not far off is to be placed another sub-family, 

 that of the Octochaetinae, which is New Zealand 

 and Indian in range, the intermediate countries being, 

 strange to say, not populated by this race of Oligo- 

 chaeta. The group contains several genera of which 

 Octochaetus, Eutyphoeus, and Dinodrilus are the 

 best known. All these worms agree in the main 

 features of their anatomy with Notiodrilus ; but they 

 have diverged in different directions. Thus in Octo- 

 chaetus the typical two pairs of gonads and glands 

 belonging to the generative system have been 

 retained, while the nephridial system consists of 

 micronephridia ; in Eutyphoeus, one pair of spermi- 

 ducal glands has disappeared, and as a general rule 

 the species of this genus have only one pair of 

 spermaries and the corresponding pair of sperm ducts. 

 They are close to Octochaetus. The third genus 

 mentioned, Dinodrilus, is a New Zealand form 

 specialised in possessing 12 setae in each segment. 

 Otherwise it is not far removed from Octochaetus. 



A fifth sub-family is also easily referable to the 

 type whose structure has been dealt with as a pre- 

 liminary to the present survey. That sub-family is 

 the Ocnerodrilinae which is American and African 

 in range. These worms are somewhat degenerate 

 in comparison with their allies. Thus the calciferous 



