^j^ Dr. Johnston on the British Annelides. 



originate, on each side, two brushes of long bristles that pro- 

 ject forwards ; similar but shorter brushes are borne by the 

 third segment, and still shorter by the fourth, but still they 

 are long enough to mix with those of the second to form that 

 hairy brush which arms the front, and so remarkably charac- 

 terizes the worm. The bristles of the other segments are not 

 longer than the breadth of the body, and are either laid over 

 the back or projected from the sides. These long bristles 

 (fig. 6, 7-) all belong to the dorsal brush, which consists of 

 seven or eight, unequal in length, setaceous, smooth, slender 

 and flexible, and closely annulated like the antenna of a lobster 

 or Gammarus ; with them are intermixed a few much shorter 

 acicular bristles that are not annulated (fig. 8.) : the bristles of 

 the ventral brush are short and also of two kinds,— one kind 

 setaceous and slender (fig. 10.), — the other stout, straight 

 until near the extremity, where it is bent into a sharp cutting 

 point: there are four or five of them in each brush (fig. 9.). 

 With a good magnifier we also discover that every one of the 

 granules of the skin is tipt with a very short rather blunt spine. 

 Anus terminal and simple. 



From its softness and flaccidity, as well as from its struc- 

 ture, we may safely conclude that this worm burrows in the 

 soil after the manner of the Arenicola, which it in fact re- 

 sembles considerably. The brush of hairs on the anterior ex- 

 tremity will be in general protruded from the furrow, and is 

 probably subservient to the capture of the prey. The hairs 

 are, in all our specimens, soiled and infested with sordes and 

 conferva-like filaments (fig. 6.), which, though they could not 

 be removed with a brush, are undoubtedly extraneous ; for the 

 hairs are not equally and alike so disfigured; for while some were 

 almost clean, others were greatly loaded with this foulness, 

 and none of it was found on the bristles of the lower seg- 

 ments. 



Plate XI. Fig. 1. Trophonia Goodsirii, natural size. 2. The anterior 

 segments from above ; and 3. The same from below, magnified. 4. Three 

 segments laid open by an incision through the ventral surface and spread 

 out. 5. A portion of the skin highly magnified. 6. One of the front bristles. 

 7. A bristle from the dorsal brush of a segment from near the middle of the 

 body. 8. Another bristle from the same. 9. A bristle of the ventral brush ; 

 and 10. One of the small ones that are associated with them. 



