STRUCTURE OF EARTHWORM OF GENUS DIAOH/ETA. 159 



On the Structure of a Species of Earthworm 

 belonging to the Genus Diachaeta. 



By 



Frank. E. Beddard, H.A., 



Prosector to the Zoological Society of London. 



With Plate XX. 



I RECEIVED some time since, through the kindness of 

 Mr. Windle, a number of examples of earthworms from the 

 Bermudas. Some of these belonged to a species of Lum- 

 bricus, while others seemed to be referable to the genus 

 Urochseta; under this generic name I described a year ago 

 in ' Nature ' the remarkable characteristics of the setae of the 

 hinder end of the body of the worm. 



I believe now that the earthworms belong to Mr. Benham^s 

 genus Diach^ta (5), though probably representing a new 

 species of that genus, which is at present only known by Mr. 

 Benham's account of the anatomy of Diachseta Thomasii. 



I cannot, however, be certain about this, as Mr. Benham's 

 description of this species is not complete, any more than is 

 the description of the Bermuda form contained in the following 

 pages. 



The worms measure about four inches in length, are com- 

 paratively stout, particularly in the anterior region, comprising 

 about the first ten segments, which is smooth and swollen. 



So far as I can see, there is no prostomium, but the mouth 

 opens terminally, as in D. Thomasii^ and in Urochseta. 



' I have been as careful as possible in ascertaining this, because I find 

 that I have made a mistake in stating that Thamnodrilus has a terminal 

 mouth and no prostomium ; Mr. Benham suggested the possibility of an error 



