l(i WILLIAM F. ALLEN 



The posterior jiortion of the lateral trunk (figs. 1-3, 4-7, 

 L.T.ixi) takes its origin from a conspicuous network on the fascia 

 (figs. 1 and 2, F.) and from the intrinsic muscles of the caudal fin. 

 In crossing the fascia it makes a slight ventral bend, and is dis- 

 tinctly a superficial vessel. It receives a prominent dorsal branch 

 and one or two ventral branches. In Ophiodon there is a notice- 

 able fan-shaped network (fig. 2, Net.) between this dorsal branch 

 and the main stem. Also at the base of the tail in Ophiodon there 

 is a mesal connection (fig. 2, L.T.^s)), which joins a swelling of the 

 caudal trunk, designated as the posterior caudal sinus. This 

 communication was clearly shown in an earlier paper (pi. 1, fig. 7). 

 The same relationship is likewise found in Clinocottus (fig. 3, 

 L.T.is)). Nothing of the kind, however, was found at the base of 

 the tail in Scorpaenichthys. In its place a branch of the caudal 

 artery was seen going to the periphery. 



What is designated as the profundus or transverse portion of 

 the lateral lymphatic trunk (figs. 4-7, L.T.{2)), namely, the 

 trunk formed by the union of the main stem and the posterior 

 portion of the lateral trunk, passes mesad to the posterior 

 lateral surface of the last centrum, where it bends dorsad in front 

 or behind the posterior neural blood vessels, to anastomose with 

 its fellow trunk on the opposite side, thus forming the source of 

 the great longitudinal neural lymphatic trunk. At some point 

 in its course it receives the posterior neural lymphatic trunk (figs. 

 4-7, P.Neu.T.), which to trace backward, travels dorsad, par- 

 allel with the corresponding blood vessel. On the side of the ver- 

 tebral column from which a posterior neural vein has its course 

 (figs. 4 and 5) this posterior neural trunk runs along the anterior 

 surface of the vein, and terminates in the corresponding profundus 

 portion of the lateral trunk at the point ^vhere the latter anasto- 

 moses with its fellow to form the longitudinal neural lymphatic 

 trunk. On the opposite side of the vertebral column, that is, 

 where the posterior neural trunk follows along a posterior neural 

 artery (figs. 6 and 7), the lymphatic vessel traverses the posterior 

 surface of the artery, and after crossing the artery it culminates 

 in the profundus portion of the lateral trunk at the point of its 

 dorsal bend on the surface of the last centrum. On one side, but 



