•2 MR FRANK E. BEDDARD ON THE 



regarded this worm with a certain amount of doubt as forming the type of a group 

 ( Aclitellians), equivalent to each of the other groups Postclitellians, Anteclitellians, &c. ; 

 the distinguishing feature of this group was the complete absence of a clitellum. 



The next paper upon the subject is by myself [1] ; it contains some notes upon a 

 species of Moniligaster, which I regarded, owing to the great discrepancies between my 

 observations and those of Perrier, as belonging to a new species termed M. Barwelli; 

 the facts put forward in this paper and illustrated by a few figures, mainly concerned 

 the anatomy of the reproductive organs. Subsequently Dr Horst [8] described a third 

 species, M. Houteni, adding facts of importance to the descriptions of both Perrier and 

 myself, and supporting my interpretation of Perrier's account of the reproductive 

 apparatus. Dr Horst's paper was wider in its scope than my own, and dealt with the 

 anatomy of the viscera in general as well as of the reproductive system. A short note 

 [2] by myself emphasised the differences in the reproductive system between Moniligaster 

 and all other earthworms, and its resemblance in this respect to some of the lower 

 Oligochseta. 



This was repeated with additions in a later paper [4], the genus being still retained 

 among the earthworms, though regarded as forming a special group with strong affinities 

 to some of the "Limicolse." 



Dr Rosa [14], in a paper upon the classification of the " Terricohe," came to the con- 

 clusion that Moniligaster was distinctively an earthworm (Rosa regards the Terricolse as 

 a group not corresponding to a group Limicolee, but to the various families — Tubificidge, 

 Lumbriculidse, &c. — which were associated together to form the Limicolse), and criticised 

 some of my own statements. 



I have already briefly [3] replied to this. 



Professor Bourne [6] in 1886, described, though very briefly, a large number of new 

 species, of which one had a fully developed clitellum, thus showing the absence of that 

 structure to be not distinctive of the genus. 



The present paper, of which an abstract appears in the Proceedings, contains a some- 

 what extended recapitulation of the facts concerning the reproductive system, with a 

 general account of the anatomy of the species Moniligaster Barwelli, which I have not 

 yet attempted ; and finally a discussion of the systematic position of the genus and its 

 relations to other Oligochseta. 



II. Anatomy of Moniligaster Barwelli. 



§ 1. External Characters. 



This is a very small species, not measuring much over one inch in length and ^ of 

 an inch in diameter at the broadest part — the head end. The ventral surface posteriorly 

 is rather flattened, while the dorsal surface is very convex. The colour of the spirit- 



