WORMS 179 



extend nearly to the end of the worm. On the ventral side of the para- 

 podia are whitish tubercles with a dark spot in the middle. These 

 papillae secrete the long, broad tube in which the worm lives. The worm 

 is difficult to capture, for when pursued it retreats quickly into its tube, 

 which is so large that it can easily turn around within it. ( Plate XL VIII.) 



Diopatra cuprea. Head and anterior part of body, showing part of the branchiae ; 

 side view. 



GENUS Arabella 



A. opalina. Body cylindncal, twelve to eighteen inches long, one 

 quarter of an inch wide in the middle, and tapers to the ends, which are 

 comparatively small ; lateral appendages short ; color bronze, with bril- 

 liant, opal-like iridescence; head small, conical, but blunt and without 

 tentacles ; four eyes in transverse row at the base of the head ; segments 

 well marked ; coils into spirals when outside of its burrow. Found in 

 compact sandy mud at low-water mark on the New England coast. 



GENUS Lumbriconereis 



L. tenuis. Twelve inches or more long, and slender, like a fine cord ; 

 bright red and somewhat iridescent ; very fragile. Abundant in sandy 

 mud on the northern New England coast, and found from New Jersey 

 northward. 



FAMILY GLYCEREDJE 



These worms are long and smooth, with numerous segments. 

 They taper at both ends. The head is small, conical, sharply 

 pointed, and has four very small tentacles. The proboscis, or 



