(i). Types of pharyngeal teeth: 



(a). Falciform — Study the lower pharyn- 

 geals of the homed dace. Draw and 

 write formula. Examine the lower 

 pharyngeals of the white sucker in 

 situ. Relation to the esophagus and 

 gill arches? 

 (b). Molariform — Examine the upper and 

 lower pharyngeals of the drum. 

 Result? The lower pharyngeals of 

 either side in this species are united 

 at the middle. When found in this 

 condition, they are said to be united 

 below. Draw, 

 (c). Villiform — Borne on pads. Examine 

 the bullhead. To which type do the 

 pharyngeals of the perch belong? 

 (i). Abdominal viscera — Remove the ventral wall of the 

 abdomen. 



(i). Peritoneum — What is its color? Compare 

 with the peritoneum of the stone-roUer 

 {Campostoma). Result? 

 (2). Identify stomach, liver, intestine, reproductive 

 organs, and air bladder. What is the relation 

 of the air bladder to the intestine ? Compare 

 with Campostoma. Result? What is the 

 relation of the esophagus to the air bladder? 

 Compare with the white sucker and bullhead. 

 Result ? What is the relation of the presence 

 or absence of spines in the fins and the 

 presence or absence of a duct between the 

 esophagus and air bladder ? Apply the terms 

 Physostomi and Physoclysti in this connection 

 (3). Stomach — -To what type does it belong? Are 

 pyloric ceca present? Compare with the 

 stomach of the bullhead and of the whitefish. 

 Results ? 

 (j). Vertebras of fishes. Employ Fig. 2 in this study, 



(i). Trunk or precaudal vertebra. Identify the 

 following parts; centrum, neural arch, 



