122 



COE AND KUNKEL. 



proper, is distinguished by a great abundance of ciliated cells 

 with very numerous short cilia and with their nuclei placed near 

 the superficial border of the cells ; while the posterior chamber, 

 or stomach, is characterized by fewer ciliated cells, and these have 

 less numerous but longer cilia, the nuclei are pressed nearer the 

 basal portion of the cells, and the gland cells contain a much 

 more granular secretion and vacuolated cytoplasm than those in 

 the anterior chamber. The rectum is longer than in many related 



ps 



cm 



I 



7> 



Qlm 



FIG. 3. Transverse section through posterior end of body, showing the very minute 

 proboscis sheath (ps), the lateral vessels (/?'), the sexual glands (sg), and the genital 

 duct (gd). The internal muscular layer (?7w) is here very much reduced while the 

 outer longitudinal muscles (oli) remain comparatively massive; M, lateral nerve; 

 in, intestine ; cm, circular muscles. 



species, and the amis opens on the dorsal surface at the posterior 

 end of the body. 



The blood vascular system presents the usual arrangement of 

 cephalic and esophageal lacunae. There is a single broad cephalic 

 lacuna (Fig. 4) situated above and beside the rhynchodaeum, 

 and extending from near the tip of the snout almost to the brain 

 region where it is divided into two lateral lacunas by the enlarge- 

 ment of the rhynchodaeum (Fig. 4). These two lacunae unite 



