1901.] NATURAL SCIENCES OF PHILADELPHIA. 



671 



B 



D 



Diagram 2. —Showing the comparative extent of the inner circular muscle 

 layer fn certain Nemerteans.— A, Carinellu an/iulata ; B, Carinella 2ioly- 

 morpha; C. Carinella linearis; D, Carinoma ; E, Zygenpoha and Mi- 

 crura cmca. The heavy lines represent the extent of the inner circular 

 muscle, the broken lines the outline of the alimentary tract. 



