DISTRIBUTION OF LYMPHATICS IN SCORP^ENICHTHYS 45 



the hyomandibular bone. Throughout its entire course the 

 lateral lymphatic trunk receives numerous dorsal and ventral 

 intermuscular or transverse vessels, which arise from a network 

 on the surface of the myotomes, and which anastomose with 

 the dorsal and ventral lymphatic trunks. The dorsal lymphatic 

 trunk (Figs. I and 4 ; D.L.V.) is found under the skin in the 

 dorso-median line, but for the most part it is a paired vessel, 

 running along on each side of the dorsal fin between the super- 

 ficial and profundus dorsal fin muscles. In the region of the 

 fins both trunks receive numerous cross-branches from the dorsal 

 fin or median dorsal lymphatic vessel, that traverses the basal 

 canal ' of the rays, and which collects the network from the 

 dorsal fin. Throughout their whole length the dorsal lymphatic 

 trunks are in connection with the intermuscular and the neural 

 or interspinal vessels. Posteriorly this trunk is continued into 

 the basal canal of the caudal fin as the caudal fin sinus, and 

 when the median line is reached, unites with the corresponding 

 ventral trunk in forming the hcemal or inferior spinal lymphatic 

 canal. The ventral lymphatic trunk (Figs. 1, 2, 3, 4 and 6; 

 V.L. V.) occupies a similar position on the lower side of the 

 body. In the region of the anal fin it is a paired vessel. Be- 

 tween the ventrals it expands into a reservoir, which receives 

 the ventral fin sinuses that collect the lymph from the ventral 

 fins. A few myotomes in advance of the ventrals it pierces the 

 ventral fin musculature and follows along the lower side of the 

 pelvics to empty into the pericardial sinus. Posteriorly it enters 

 the basal canal of the caudal fin as the caudal fin sinus, and as 

 described above anastomoses with the dorsal and haemal trunks. 

 Throughout its entire course it is in connection with the ventral 

 intermuscular or transverse vessels and the hcemal or interspinal 

 lymphatic vessels. The most cephalic of the ventral inter- 

 muscular vessels is much larger than the others and is desig- 

 nated as the pectoral sinus (Figs. 1, 2, 3, 4, 5 and 6, P.S.). 

 It receives the common trunk formed by the union of the 2 

 large sinuses situated on either side and at the base of the pec- 



1 Immediately distad to the basal articulation of each raj there is a sort of for- 

 amen, here designated as the basal foramen of the fin or the fin-ray. Trois 

 calls it cruna (eye of a needle). 



