140 HUNTINGTON. 



the ventro-mesal aspect of the stem-bronchus, opposite the origin 

 of A" from the ventro-lateral surface. 



The corresponding artery occupies a pecuHar position. In- 

 stead of winding around the angle between stem-bronchus and 

 A" caudad of the latter (see preceding types), the artery is de- 

 rived from the caudal surface of the main pulmonary artery 

 opposite the point where from the cephalic margin the apical 

 vessel accompanying A' takes its origin. The artery descends 

 on the ventral aspect of its bronchus. A similar bronchus is 

 found on the left side, but the corresponding arterial branches 

 are short trunks passing to their distribution from the main 

 pulmonary artery dorsad of the stem-bronchus. 



VII. Cebus capucinus — Capuchin Monkey. 



Corrosion of bronchial system and pulmonary artery. 

 Columbia University Museum, No. 488. PL XXII, Ventral 

 view. PL XXIII, Dorsal view. 



This type presents a somewhat peculiar arrangement of the 

 cephalic trunks on both sides. 



On the right side the separation of the two branches A' and 

 A" is complete, the pulmonary artery occupying the interval 

 between them. A' has migrated cephalad on the stem- 

 bronchus, becoming " eparterial," and corresponding to the 

 usual mammalian type of the right side. 



On the left side the migration of the cephalic trunk A is com- 

 plete compared with the preceding form [AucheJtia). It is 

 placed cephalad and dorsad of the point of accession of the main 

 pulmonary artery to the stem-bronchus, and divides into the 

 two secondary branches A' and A" . 



We have, therefore, to follow Aeby's nomenclature for the 

 moment, a "bilateral eparterial system." The eparterial 

 bronchus of the right side, as usual, being furnished by the di- 

 vorced and migrated apical branch A' , whereas, on the left side 

 the entire cephalic trunk A, with its secondary branches A' and 

 A", becomes "eparterial." 



