CRUSTACEANS IX CIL-ETOI'TI K I ^ II 



(Exuvella), fine silt, and other unidentifiable particles. Five 

 Polyonyx stomachs examined August 9 contained: diatoms, silt, 

 algal filaments, and spores or cysts. The commensals apparently 

 feed on such organic matter as can be strained from the water 

 passing through the worm tubes in which they live. 



Enders ('05) points out that a prolonged breeding period 

 characterizes Polyonyx and Pinnixa, and he believes this con- 

 dition is due to the protection afforded by the worm tubes. 



FIG. 4. The endopod of the third maxillipjd of Polyiv\- "the fishing net." 

 The long setae on the four distal segments are plumDse (rut slu.vn in the figure). 

 FIG. 5. First antenna (antennule) of Polyonyx. 



Every female he took at Beaufort, from June 21 to October 25, 

 bore eggs or had recently shed them. Every female taken by 

 the writer at Woods Hole (July 18 to August 9) bore eggs or 

 young. Four females shed their zoea in the dishes where they 

 were kept in the laboratory. The bluish eggs of Pinnixa are 

 well protected by the broad abdomen which folds tight against 

 the body, and completely covers them. Those of Polyonyx are 

 bright red; they project so that they are not concealed by the 

 abdomen and appear as a bright mass between the body and the 

 chelipeds when the crustacean is viewed from above (Fig. 20). 



