THE HEART AND ARTERIES OF POLYODON 



413 



lym., lymphatic vessel 



m.adm., m. adductor mandibularis 



m.adh., m. adductor hyomandibularis 



m.bmd.m.bmd.,' origin and insertion 

 of m. branchiomandibularis 



m.lev. (1,2,3,4), na. levator arcuus 

 branchialis 



m.obv. (1,3,3,4), Di- obliquus ventralis 



m.pr., m. protractor mandibularis 



m.sthy., tendon of sternohyoide\is mus- 

 cle 



no., notochord 



oc, oral cavity 



oper., operculum 



os.den., dentary bone 



OS. mx., maxillary bone 



os.pa., parasphenoid bone 



os.ps., post scapula 



pc, pericardial cavity 



rec, rectum 



rsp., respiratory folds 



sb., swim bladder 



si., small intestine 



spi., spiracle 



spl., spleen 



St., stomach 



sv., sinus venosus 



thy., thyreoid gland 



v.dc, duct of Cuvier 



v.hp., hepatic vein 



v.j., jugular vein 



v.ji., inferior jugular 



v.p., portal vein 



c.pc, post cardinal vein 



ven., ventricle 



Fig. 1 A conus arteriosus cut along the midventral line and spread open, 

 this specimen there are but three valves, one of which has an extra cusp. 



In 



JOUKNAL OF MOEPHOLOOT, VOL. 23, NO. 3 



