SECTION THROUGH PHARYNX. 



213 



of a single layer of very long and slender flagellate 

 cells, resting on a thin outer wall of connective 

 tissue. 



44. Aiuphioxus lanceolatus. Transverse section through the 

 hinder part of the pharynx of an adult female, passing through the 

 liver and ovaries. The boundary of the atrial cavity is indicated 

 by a thick black line. (a. m. m.) 



A, skeleton of dorsal fin. B, spinal cord. C, notochord. D, connective- 

 tissue sheath of notochord. E, cavity of pharynx. F, epibranchial groove. 

 G, endostyle. H, atrial cavity. L, liver. M, dorsal ccelomic canal. N, 

 branchial ccelomic canal. O, coelomic space surrounding liver. OV, ovary. 

 P, metapleural canal. R, left dorsal aorta. S, endostylar ccelomic canal. T, 

 hepatic veins. 



3. The atrial cavity has the same general relations as in 

 section B. The atrial epithelium covers the outer 

 surfaces of the branchial bars, and the suspensory 



