312 ZOOLOGY SECT. VH 



spindle-shaped with flattened ventral surface. The ventral surface bears two 

 longitudinal bands of cilia ; the dorsal is non-ciliated, but bears a number of 

 longitudinal rows of slender pointed cuticular processes. The aboral end is 

 narrow and bifurcated. The mouth, situated at the anterior end, is provided 

 with a circlet of hooked setae ; it leads into a muscular pharynx ; the intestine 

 is straight, and terminates in an anal aperture situated near the aboral end. 

 The nephridia are a pair of unbranched coiled tubes. There is a cerebral 

 ganglion at the anterior end, giving off a pair of ventral longitudinal nerves ; a 

 number of sensory cilia occur at the anterior extremity. 



