46 



ALLEN 



toral fin, and each of these sinuses is in communication with 

 cross-branches from the median pectoral fin sinus, lying within 

 the basal canal and collecting the pectoral fin network. 



Two principal trunks constitute the main profundus or sub- 

 muscular system. The dorsal one, which is undoubtedly the 

 largest and most important vessel in Scorpamichlhys, is desig- 

 nated as the my clonal or superior longitudinal lymphatic trunk 

 (Figs. 4 and 5, My.L. V.). It runs in the spinal canal directly 

 above the cord from which it is separated by a septum. Be- 

 tween the skull and atlas it divides, and both forks after passing 

 laterad out of this canal unite with the lateral lymphatic trunks 

 in forming two common vesicles that finally terminate in their 

 respective cephalic sinuses. In the region of the last vertebra 

 this trunk again bifurcates to unite with the lateral trunks in 

 forming joint papillae that undoubtedly empty into the right and 

 left forks of the caudal vein. Along its entire course it receives 

 numerous neural or interspinal vessels that communicate above 

 with the dorsal trunk, and which are often prolonged ventrally to 

 unite with the longitudinal haemal or inferior spinal lymphatic 

 trunk and the abdominal sinus. Since the longitudinal hcemal 

 or inferior spinal lymphatic trunk does not come under the head 

 of this paper it has not been figured. It travels in the haemal 

 canal, is continuous posteriorly with the dorsal and ventral 

 trunks, and anteriorly it appears to empty into the abdominal 

 sinus. Within the haemal canal it receives the haemal or inter- 

 spinal vessels, which are also in communication with the ven- 

 tral lymphatic trunk. The abdominal sinus (Figs. 4, 5 and 6, 

 Abd.S.), which lies directly under the kidney and empties 

 anteriorly into the cephalic and pericardial sinuses, receives nu- 

 merous small lymphatic vessels from the reproductive organs, 

 the great lymphatic trunk from the viscera, and many inter- 

 costal vessels that are also connected with the profundus ven- 

 tral lymphatic trunk. The latter vessel (Figs. 4, 6 and 9, 

 V.L. V. 1 ) perhaps should have been included as one of the prin- 

 cipal profundus longitudinal trunks. It pursues a similar course 

 to the ventral lymphatic trunk along the lower wall of the visceral 

 cavity and terminates anteriorly in the posterior end of the peri- 

 cardial sinus. Several interlinking vessels were noticed in the 



