FISHERY BULLETIN: VOL. 71, NO. 2 



the submucosa below the dorsal epithelial layer 

 is thicker than beneath the ventral layer. A 

 flaplike structure directed posteriorly was ob- 

 served on the ventral side of the tongue. Sen- 

 sory organs, consisting of numerous sensory 

 cells provided with hairletlike processes, occur 

 on the tongue (Figure 6) and open into the 

 pharynx through a gustatory pore. 



Esophagus and Esophageal -Intestinal Valve 



Posterior to the pharyngeal teeth, the 

 pharynx constricts markedly to form a short 



muscular tube, the esophagus, which opens 

 directly into the intestine through a muscular 

 valve. Distinct longitudinal ridges (Figure 7) 

 continue from the pharynx to the esophageal- 

 intestinal valve and then diverge in the in- 

 testine. There are no transverse connecting 

 cores between the longitudinal folds. These 

 folds branch shortly anterior to the esophageal- 

 intestinal valve (Figure 8). The mucous cells 

 in the epithelium disappear in this region 

 (transitional zone). This is more prominent in 

 small specimens (less than 40 mm SL) than 

 in larger specimens (200 and 210 mm SL). 



''^f Sk 



Figure 7. — Longitudinal ridges of the 

 anterior esophagus of a 40-mm SL 

 juvenile cunner (X 40, x.s.). ar, 

 areolar connective tissue; cm, circu- 

 lar muscle layer; L, liver; m, mucous; 

 Sk, skeletal muscle; sr, serosa; st, 

 striated muscle. 



Figure 8. — Transitional zone anterior 

 to the esophageal-intestinal valve in 

 the esophagus of a 40-mm SL cunner 

 (X 40, X.S.). ad, adventitia; cm, 

 circular muscle layer; g, granulocyte; 

 K, kidney; L, liver; m, mucous 

 secreting cell; Sk, skeletal muscle. 



570 



