114 A. S. PEARSE. 



Shelford, V. E. 



'n Physiological Animal Geography. Jn. Morphol., 22, pp. 551-618. 

 Stebbing, T. R. R. 



'93 A History of the Crustacea. Recent Malacostraca. New York, xvii 



466 pp. 

 Van Beneden, P. J. 



'76 Animal Parasites and Messmates. London, xviii+274 pp. 



EXPLANATION OF PLATE I. 



FIG. 7. Section of a Chcetopterus tube in the sand. It contains a worm in the 

 lower part. On the left a male (above) and a female Polyonyx are clinging to the 

 wall of the tube. The male is cleaning his back with the comb on the tip of his 

 last leg; the female rests with her ventral side toward the observer. Drawn from 

 life by Miss Barbara Bradley. 



