NEREIS. 147 



PLATE XXI. 



FIG. 8. Section of fig. 4, enlarged. 



9. Proboscis of a middle sized specimen. 

 10. Proboscis of a large specimen. 



4. NEREIS BULLATA The Knob Nereis. Plate XXII. Figs. 1, 2, 3, 4, 5. 



Length above two inches ; body flattened, composed of numerous 

 principal segments, with two interannulations between each ; a row of 

 pencils down each side, the pencil consisting of some short hairs, issuing 

 from under the knob. A small forked projection terminates the ante- 

 rior extremity ; the posterior ends in two knobs. Towards the anterior 

 extremity are two crescents, each consisting of two or three specks, the 

 horns of the crescent turning outwards. Colour universally yellow. 



When exposed to the light, this animal wraps itself up as a crescent. 



Marine. Rare. 



PLATE XXII. 



FIG. 1. Nereis bulletin. 



2. Specimen, enlarged. 



3. Anterior portion, more enlarged. 



4. Posterior extremity, enlarged. 



5. Middle section, enlarged. 



5. NEREIS PARVA. Plate XX. Figs. 23, 24, 25. 



I speak of this animal provisionally, being ignorant whether it is 

 adult. 



Five or six specimens appeared in a vessel of sea- water in September. 



Length five lines ; body slender. Antennae two, long and flexible. 

 Head rather triangular, somewhat prolonged in front, on each side of 

 which is a black eye like a crescent. The body seems almost quite 

 smooth, perhaps from the faintness of annulations. I could not observe 

 hairs or bristles, but it terminates in two leaves. 



