192 OLIGOCHAETA 



These points taken together J are such as to render the inclusion of Fdodrilus 

 in any other family but the Phreoryctidae impossible ; the only other alternative 

 would be to create a separate family for its reception, which appears to be 

 unnecessary. 



(i) Pelodrilus violaceus, BEDDARD. 



Pelodrilus violaceus, BEDDARD, Trans. Roy. Soc. Ed. Vol. xxxvi. Pt. ii. (1891) 

 p. 301. 



Definition. Progtomium short. Nephridio-pures in front of ventral setae. Septal glands in 

 V-VII. Chloragogen-cells covering alimentary tract commence in V. Sensory papillae two 

 one behind the other on segment X. Habitat N. Zealand. 



As only one species of the genus Pelodrilus is known, the above generic and 

 specific definitions will doubtless ultimately require revision. The species occurs in 

 rich, wet soil, at a little distance from a swamp near Ashburton, New Zealand. In 

 connexion with its terrestrial habit, the thickening of the integument and of the 

 septa in the anterior part of the body (septa v/xi) is of interest. 



FAMILY MONILIGASTRIDAE. 



DEFINITION. Large or small earthworms, with paired setae, eight per segment; 

 clitellum X-XIII ; male pores X/XI or XI and XII ; sperm-ducts open into 

 segment in front of that which bears the external pore ; spermiducal gland 

 showing the same structure as in the Lumbriculidae, with sometimes a pro- 

 trusible penis. 



This family of earthworms is in many ways exceedingly remarkable ; the 

 genus Moniligaster for a long time the only genus of the family was originally 

 made by PERRIF.R (3), its describer, into a separate group called Aclitellians, 

 equivalent to the three other groups into which PERRIER divided the terrestrial 

 Oligochaeta ; this step was taken on account of the apparent absence of that 

 characteristic organ the clitellum. A clitellum was, however, recognized by BOURNE 

 (2) in a large species, M. grandis, some feet in length, where it would naturally 

 be more obvious than in the small M. deshayesi ; the apparent absence of the clitellum 

 is to be probably explained by the fact that it is only periodically developed, as in 

 the aquatic Oligochaeta ; in addition to this possible explanation of the failure of most 



1 The above characters hardly differentiate Pelodrilus from Lumbricus ; as, however, I am here comparing 

 Pelodrilus with Phrearyctes there is, perhaps, hardly any need to point out the more important facts which 

 distinguish both from Lumbricus. 



