232 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



ceratal sinus; dlv, dorso-lateral vein; Oliver; V, lateral 

 lobes of liver ; Is, blood lacunae in mesoderm ; m, muscle 

 bands ; mt, muscular tissue ; pc, pericardial cavity ; r, 

 rectum ; v, ventricle. 



PL XV. a, nerve arising from the pleural ganglia 

 (epipodial nerve) ; b, nerve arising from the dorsal surface 

 of the pedal ganglia (the dorsal pedal nerve) ; c, branch 

 nerve arising from the dorso-pedal nerve ; d, branch 

 nerve arising from the epipodial nerve ; a -f c, the nerve 

 formed by the union of the epipodial with the branch c, 

 from the dorsal pedal nerve ; cce,*ccelome ; oe, oesophagus ; 

 p.g., pedal ganglion; pl.g., pleural ganglion; p.n., pedal 

 nerve. 



Plate XIV. 



Fig. 1. Horizontal section through the portion of the 

 body of Dendronotus arborescens which bears 

 the first and second pairs of cerata, and passing 

 through the upper part of the visceral mass. 

 The anterior end of the section is relatively 

 higher than the posterior so that the anterior 

 pair of cerata are seen almost separated off from 

 the body, but the posterior pair are not yet 

 distinguishable, the section passing below them. 



Fig. 2. Taken from a section fifteen in number higher in 

 the series than fig. 1. The bases of the anterior 

 cerata are shown, cut through transversely and 

 completely separated from the body; and the 

 posterior pair are seen as distinct prominences 

 at the sides. 



Fig. 3. Taken from a section thirty higher in the series 

 than fig. 2. The upper parts of the first pair of 

 cerata are seen, cut transversely ; and the second 

 pair are cut through their bases and almost 

 completely separated from the body. 



