TROPHONIA. 225 



Front armed with a brush of long hair-Hke finely iridescent bristles. 

 Segments between 50 and 60, homologous, narrower than broad, 

 granulous, somewhat puckered and thickened on the sides, on which 

 there are two distant bundles of non-retractile bristles, but no papil- 

 lose feet. Eirst segment very small, and as it were drawn within 

 the second : mouth subterminal, circular, edentulous. The second 

 segment is rather less than the third, and from its anterior edge 

 there 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 characterizes 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 (figs. 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 Lob- 

 ster 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 tipped with a very short 

 rather blunt spine. Anus terminal and simple. 



From its softness and flaccidity, as well as from its structure, we 

 may safely conclude that this worm burrows in the soil after the 

 manner of the Arenicola^ which it in fact resembles considerably. 

 The brush of hairs on the anterior extremity will be in general pro- 

 truded 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 ; 

 but 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 segments. 



(«) Berwick Bay, Dr. Johnston. 



(b) Firth of Forth, Lieut. Thomas^ R.N. 



(c) Shetland, Professors Goodsir and E. Fo7'bes. 



Plate XIX. Fig. 1 . Trophonia plumosa, 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. 



