66 BRISTOL. 



DESCRIPTION OF PLATE V. 



Dorsal view of the central nervous system of Nephelis in the first seven and 

 part of the eighth metameres as reconstructed from surface views and sections. 

 X 30 (circa). The metameres are indicated on the left of the drawing by Roman 

 numerals, the annuli are numbered by Arabic figures on the right. The nerves 

 are also numbered with Roman numerals. Dorsal sensillae appear as black 

 circles; ventral sensillae as light circles, e.xcepting in the first five annuli, where 

 they are drawn as they appear in a surface view of a specimen killed and examined 

 in Haller's fluid. The details of distribution are shown so plainly as to do away 

 with the need of explanatory references. On the left side, omitted from the right 

 for clearness, are seen the long bipolar cells (long b.p.c.) that connect the inter- 

 muscular nerve rings. They are found at the junctions (Junctions) of the nerve 

 branches with the rings, and the cut end of these branches are represented on that 

 side. Faivre's nerve is indicated at F.N. The first pair of nephridiopores {ist 

 nj>fi.f.) lie between the i6th and 17th annuli. 



