PLATE XXII 



FIG. i. Ltneus rubescens Coe. Transverse section of head in front of brain, 

 showing distribution of cutis glands (cugl}, the highly developed cephalic glands 

 (cgl*), and the duct (a) leading forward beneath the rhynchodaeum (rfi). This 

 duct is probably the common efferent canal for the secretions of the more pos- 

 terior cephalic glands ; cf, cephalic furrow ; bl, blood lacuna ; cm, circular muscles. 

 XSo. 



FIG. 2. Carinella frenata Coe. Portion of transverse section of head, show- 

 ing the deep ciliated pit (cf) from which a ciliated sensory canal (cc) leads inward 

 to the brain region, where it becomes surrounded with sensory nerves (sn) from 

 the dorsal side of brain to form a highly specialized sense organ ; /', integument; 

 _/?, layer of fibrous connective tissue surrounding brain ; cm, circular muscles ; 

 br, fibrous core of brain, surrounded except internally by a thick layer of nerve 

 cells ; bm, basement membrane. X 60. 



FIG. 3. Carinella frenata. Portion of transverse section of body through 

 lateral sense organ; /, integument, sharply contrasted with the layer of special- 

 ized sensory cells lining the sensory pit; /, lateral nerve; Zv, lateral blood 

 vessel ; sep, epithelium of stomach ; icm and ocm, inner and outer circular mus- 

 cular layers ; Im, longitudinal muscles. X 60. 



FIG. 4. Tetrastemma bih'neatum Coe. Portion of transverse section of body. 

 The two pigment bands (pig) which give the body its characteristic markings 

 are situated in the midst of the longitudinal muscles (Im), on either side of the 

 proboscis sheath (re) ; tne, intestinal epithelium ; other reference letters as in 



fig- 2. X23. 



(220) 



