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 rhjnchodaeum {rli). 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. 

 X8o. 



Fig. 2. Carznella frenata CoQ. Portion of transverse section of head, show- 

 ing the deep ciliated pit {cp) from which a ciliated sensory canal {cc) leads inward 

 to the brain region, where it becomes surrounded with sensory nerves (5«) from 

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

 /I, 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. Cart'nella frenaia. 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; In, lateral nerve; Iv, lateral blood 

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

 cular layers ; Im, longitudinal muscles. X ^o- 



Fig. 4. Tetrastemma bilineatum Coe. Portion of transverse section of body. 

 The two pigment bands {^fig) which give the body its characteristic markings 

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

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



fig- 2' X230- 



(220) 



