12 MR FRANK E. BEDDARD ON THE 



resemblances are rather with earthworms, though among the Enchytrseidse paired sperm 

 sacs are met with (see Michaelsen, 15, plate, fig. 3), but not paired egg sacs. 



The genus in fact must be regarded as forming a distinct group related to the Lum- 

 briculidse, Phreoryctidse (1), and Lumbricidse, but coming closer to the two former than to 

 the latter. Its resemblances to earthworms, in fact, are almost entirely confined to those 

 structural features which are in direct relationship to the mode of life of the worm; i.e., 

 gizzard, vascular supply, thickened body- walls, septa, and setae. If I were compelled to 

 adopt Claparede's divisions of Terricolse and Limicolse, I would refer Moniligaster to the 

 latter. 



As it is, the following phylogenetic diagram seems in the present state of our know- 

 ledge to express the relationships of this remarkable Annelid : — 



Tubificidue. 



Moniligaster. 

 Naidomorpha. 



Phreoryctidse. 



Perichsetidse. 



The principal facts in the anatomy of Moniligaster Barwelli are the following : — # 



tl. The setae are strictly paired ; the distance between the two pairs of each side is 

 considerably greater than that between the ventral pair and the ventral median line, and 

 considerably less than that between the dorsalmost pair and the dorsal median line. The 

 setce differ greatly in size, but are not peculiar in shape, being like those of most earth- 

 worms. 



t2. Dorsal pores are present. 



t3. The prostomium is very small, and does not extend over the peristomial segment. 

 4. The dissepiments separating segments V/VI, VI/VII, VII/VIII, VIII/IX, are 

 very much thickened. 



* I do not attempt to discriminate between what are generic and what are specific characters ; there are not sufficient 

 data to do this with much probability of success. 



t The dagger indicates that the statement to which it is prefixed is made for the first time in the present paper. 



