38 WILLIAM F. ALLEN 



(fig. 2) this network in the fascia assumes the form of a fan. 

 In Scorpsenichthys there is no commimication at the base of the 

 caudal fin between this trunk and the posterior caudal sinus ^ 

 but in Clinocottus and Ophiodon there are very distinct connec- 

 tions. 



Opposite the last vertebra the main and the posterior portions 

 of the lateral trunks may be said to fuse and form the profundus 

 portions, which pass mesad and anastomose at the beginning of 

 the neural canal to form the great longitudinal neural lymphatic 

 trunk. 



The structure of the longitudinal lymphatic trunks are very 

 much the same, they are made up for the most part of a dense 

 fibrous layer, which is lined with endothelium. Notwithstanding 

 the enormous size of these canals they contain but very few cor- 

 puscles, and strange to say the red greatly outnumber the white. 



Respecting the distribution of the blood vessels previously 

 given in detail, a few points are deserving of special mention. 



The so-called minor caudal artery has an entirely different ori- 

 gin in Scorpsenichthys than was described for it by Favaro in 

 numerous Teleosts, where it was said to arise from branches of 

 the segmental arteries. So far as could be determined in Scor- 

 pa^nichthys ic nad no connections with the intersegmental arteries, 

 but rather arose from the dorsal aorta in the body cavity, and con- 

 tinued parallel with it and the caudal artery to the tail ; where it 

 separated into a dorsal and ventral minor caudal fin arteries, 

 which gave off a minor caudal ray artery for each ray. These 

 branches, however, could not be traced caudad of the intrinsic 

 muscles. In places within the haemal canal, the minor candal 

 arteries gave ofif branches of almost equal caliber to itself. The 

 function of these branches appears to be to furnish nutrient 

 arteries for the blood vessels and possibly for the lymphatics 

 of the ha>mal canal. 



There are three distinct varieties of intersegmental arteries and 

 veins, arising from the caudal artery or terminating in the caudal 

 vein. The first or lateral vessels simply curve around to the side 

 of the centra and then pass laterad in the intermuscular septa to the 

 periphery. The second or combined lateral and neural trunks 



