SEGMENTATION OF CEUTAIN POLTCH^TES. 



539 



The occurrence of right-handed and left-handed spirals not 

 only in the same individual, but very close together in the same 

 individual, is well shown. The three spirals bracketed in the 

 second specimen deserve special mention, as we have here a 

 second case of spiral within spiral. The arrangement is shown 

 in fig. 6, and can easily be understood by reference to its key 

 (fig. 6 b). It will be seen that there are two short spirals 

 of one coil each, both inside a larger one of two coils. 

 I hope in a short time to have specimens of Halla at my dis- 

 posal for dissection, and feel sure they will yield interesting 

 results. 



With regard to other Eunicidae, I have looked through a 

 fairly large number of specimens belonging to the genus Eunice 

 and to the genus Marphysa, a few Diopatras, one very long 

 Arabella (with over nine hundred segments), and two or three 

 other species of the genus Lumbriconereis, but without finding 

 any irregularities in the segmentation. 



The only other Polychsetes in which I have, so far, noticed 

 what appears to be spiral segmentation is a Sab ell a. There 

 are in the Madras collection four specimens of what I believe 



* The parapodia on the right side of Segments 115 — 118 had been pre- 

 viously removed in this specimen, evidently by some one who had noticed the 

 peculiarity. I cannot, therefore, be certain where the spiral ends. 



