DISTRIBUTION OF LYMPHATICS IN SCORPyENICHTHYS 67 



(Fig- 3, Hh.S.L. V.) arising from the hyo-hyoideus superior 

 muscles and the branchiostegal membrane. Directly behind the 

 inter-hyal the posterior hyoidean trunk expands into a reservoir 

 designated as the hyoidean sinus (Figs. 3 and 4, Ilyo.S.). This 

 sinus also receives the anterior or dorsal hyoidean trunk (Figs. 

 3 and 4, A.Hyo.T.), which runs along the upper and anterior 

 edge of the epi- and cerato-hyals, and in front of the inter-hyal 

 swells up into a sort of a sinus from which a papilla crosses the 

 outer surface of the inter-hyal and empties into the main hyoi- 

 dean sinus. At about the center of the arch quite an important 

 branch was seen to join it from the genio-hyoideus muscle. 

 This vessel (Figs. 2 and 3, Gh.L. V.) after passing along the 

 inner ventral surface of the muscle, crosses the first and second 

 branchiostegal rays, and at this point makes a sharp curve to 

 cross the outer surface of the cerato-hyal and empty into the 

 anterior hyoidean trunk. The main hyoidean sinus (Fig. 4, 

 Ilyo.S.) gradually tapers down dorsally into a papilla that 

 empties into the cephalic sinus from below and to the rear, and 

 ultimately reaches the jugular through it. This system of 

 lymphatic vessels appears to have been almost entirely over- 

 looked. The only reference found is that of Hyrtl (7, p. 2 37)» 

 where he represents the lymphatics from the tongue and branchi- 

 ostegal rays as emptying into the lateral trunk near the cephalic 

 sinus. 



This concludes the description of the distribution of the 

 lymphatic trunks of the head, dorsal, ventral and pectoral fins 

 of Scorpcsnichthys, but 2 important sinuses into which they 

 empty, and which ultimately terminate in the venous system 

 remain to be described. 



7. CEPHALIC SINUS. 



With the salmon Vogt (1, p. 136) represents the cephalic 

 sinus as being an expansion of the lateral lymphatic trunk at 

 the cephalic end of the thorax, which lies under the clavicle and 

 has a slit covered by a valve that leads into a vessel about the 

 diameter of a pin head, which terminates in the sinus of Cuvier 

 near the jugular. This sinus is said to have 3 other openings 

 that are also defended by valves. In brief the first comes from 



