164 



THE ELASMOBRANCH FISHES 



the ventricle. About midway of the eoniis it sends a branch to the ventral side 

 of the ventricle. The right coronary passes around to the ventral side of the 

 conus, supplying branches to the tissues on the right side and to the ventral 

 and dorsal parts of the ventricle and to the auricle. A posterior coronary 



m.hb 



Fig. 154 



Fig. 153 



Fig. 153. Hypobrancliial arteries, Heptanchus maculatus, dorsal view. (Marie Weldt, orig.) 

 a.dl., anterior dorsolateral artery; a.l., anterior lateral artery; Ir.a., brachial artery; 

 ce., coeliac axis; C7n.-'^, second and sixth commissural arteries; en., connective; co.a., cora- 

 coid artery; cr.l., left coronary artery; cr.p., posterior coronary artery; e.c, external ca- 

 rotid; L/i b., lateral hypobranchial; -m./i &., median hypobranchial; mi., metapterygial artery ; 

 pc, pericardial artery; p.dl., posterior dorsolateral artery; p.s., posterior scapular; s.cl., 

 subclavian artery; th.^-", anterior and posterior thyroid arteries; I -VI, first and sixth bran- 

 chial clefts. 



Fig. 154. Epigastric artery (epg.), Heptanchus maculatus, ventral view. (Cecil Rowe,orig.) 

 mJih., median hypobranchial ; r.pc, right pericardial; VI-VII, sixth and seventh bran- 

 chial clefts. 



{cr.p., fig. 153), arising from each coracoid artery, passes inward to supply 

 the sinus venosus. 



From the ventral angle of the first efferent-collector loop a posterior thyroid 

 (th.-, fig. 153) is given oi¥ which in general position takes the place of a first 

 commissural. From about the same position or a little more anterior than the 

 posterior thyroid the large external carotid artery' {e.c, figs. 151 and 153) 

 passes forward and the stem then divides, one part passing inward to the sym- 



