58 ALLEN 



vessels. Mesad of these ventral fin musculature lymphatic ves- 

 sels there are still two other ventral fin musculature vessels 

 (Fig. 2, V.M.L. V. w ), which run between the internal and 

 external ventral fin abductor muscles, and unite with the main 

 ventral trunk immediately before it penetrates the musculature 

 to empty into the pericardial sinus. 



From the above description of the termination of the ventral 

 fin vessels into a single sinus outside the fin it will be noticed 

 that this is a very different arrangement from that found in the 

 dorsal and pectoral, where these vessels emptied into a median 

 sinus, which traversed the basal canal of the rays, and having 

 numerous transverse branches, communicating with the two 

 lateral sinuses, lying at the base of the fin. 



In the paragraph on the lateral lymphatic trunk it was stated 

 that a typical ventral intermuscular or transverse lymphatic 

 vessel connected the lateral with the ventral lymphatic trunk. 

 The most cephalic of these vessels, however, show some devia- 

 tion from this general plan. The first one connects the pectoral 

 sinus with the anterior end of the ventral trunk ; the second 

 interlinks the pectoral sinus with the ventral fin intermuscular 

 vessel ; the third and fourth communicate with the lateral trunk 

 and the ventral fin intermuscular vessel ; the fifth unites with 

 the lateral trunk and the ventral fin sinus ; while the sixth ex- 

 tends from the lateral trunk to the ventral sinus. 



4. PROFUNDUS LYMPHATICS OF THE TRUNK. 



The profundus ventral lymphatic tru?ik (Figs. 3 and 4, 

 V.L. V. (1) ), which seems to have escaped the notice of the pre- 

 vious investigators, pursues a parallel and somewhat similar 

 course to the main ventral tymphatic trunk between the great 

 lateral muscles, but follows along the inner or visceral side of 

 them. So far as could be ascertained it arose near the vent and 

 passing cephalad along the median line close to the visceral 

 cavity, terminated in the posterior end of one of the pericardial 

 sinuses (Figs. 4, 6 and 9). Throughout its course it receives 

 or gives off numerous intercostal lymphatic vessels (not shown 

 in any of the figures), which follow along the inner side of 

 the intermuscular septa, parallel with the intermuscular or trans- 



