LYMPHATICS IN TAIL REGION, SCORP^NICHTHYS 25 



to have its origin behind the posterior dorsal fin and to encircle 

 the bases of both dorsal fins. On the anterior fin a secondary 

 elliptical stem (pi. x, fig. 3, 7) is represented as rising from the 

 posterior end of these elliptical vessels and after crossing the lat- 

 eral surface of the fin terminates in the anterior end of the same 

 vessel from which it takes its origin. Mayer (pp. 316-7) states 

 that Parker's description of the caudal ending of these cutaneous 

 trunks is insufficient; for he finds that the dorsal vein empties 

 into laterals, which in turn join the ventrals, and the latter being 

 paired at the origin of the tail soon terminate in the caudal vein. 

 Mayer likewise portrayed the dorsal subcutaneous vein (pp. 333-4) 

 as encircling the bases of the dorsal fins as vense circulares (pi. 

 xvii; fig. 17, vcirc.) At the posterior insertion of the fin, namely 

 at the point of division of the dorsal fin, a reservoir of consider- 

 able size was formed into which emptied a vena postica, coming 

 from the posterior part of the fin, and the vena profunda (pi. 

 xvii; figs. 21, 22, and 24, vproj.), which, in addition to communicat- 

 ing with this sinus also joined the caudal vein. 



With the Ganoids, Hopkins noted with Amiatus that the dorsal 

 lymphatic trunk after leaving the dorsal fin separated into two 

 branches, which anastomosed with the lateral trunks near their 

 termination in the caudal sinuses. The ventral lymphatic trunk 

 was portrayed (pp. 372-3 and fig. 11, v.) as beginning as a large 

 canal (fig. 11, o.) at the base of the caudal fin, which in one in- 

 stance was said to send off a communicating branch (t) to the 

 lateral trunk. As stated previously the lateral lymphatic trunks, 

 into which all the lymphatics of the tail region were discharged, 

 emptied into two caudal sinuses (fig. 11, s.) which were situated 

 below the last vertebrae, communicated with each other, and 

 culminated in the caudal vein. In an earlier paper I found in 

 Lepisosteus that there were two conspicuous caudal sinuses 

 situated under the caudal vertebrae, which emptied into the caudal 

 vein. Posteriorly one of these sinuses received a caudal trunk 

 from the caudal fin, which in reality is a continuation of the ven- 

 tral subcutaneous trunk through the basal canal of the caudal 

 fin. Into each of the caudal sinuses, a sinus disignated as sinus 

 (x) emptied its contents. The latter were described and figured 



