246 CILIATE FIBRILLAR SYSTEMS 



three or four fibrils, parallel or twisted after the manner of a rope, which 

 originate below the pellicle at the anterior end and extend posteriorly 

 a short distance beyond the mouth. The individual fibrils gradually be- 

 come thinner toward the posterior end, where they come in contact with 

 the limiting membrane formed by some of the fibrils of the peripheral 

 system. At the anterior termination of these fibrils is found a knob-like 

 structure which may be imbedded in the epithelium of the host. 



The peripheral system of fibrils is arranged in two conspicuous arches 

 along the left anterior border of the organism. Anteriorly, fibrils extend 

 both to the right and to the left peristomal lips. Posteriorly, the two 

 arches converge. Some of the fibers continue mesially and come to form 

 a kind of limiting membrane beyond which no fibrils are traceable. 



The group of fibers forming the axial system, together with the borer 

 attached at its anterior end, is called the boring apparatus, as the first 

 of its kind to be noted. It may be compared with the axostyle of some 

 flagellates. 



The peripheral system is believed to represent morphonemes. 



Methods 



Fixatives: Brasil's modification of Bouin-Duboscq's (for whole mounts), 



Bouin's alcoholic, twenty-four hours (for sections 5 \i.) . 

 Stai)i: Heidenhain's haematoxylin (whole mounts and sections). 



Fabrea salina Henneguy (Ellis, 1937). — In Fabrea there are numer- 

 ous longitudinal rows of closely set body cilia (in pairs). These are 

 interrupted on the ventral side by a coiling adoral zone. The basal gran- 

 ules are connected by fine longitudinal fibrils. No transverse connections 

 or ciliary rootlets were observed. Each membranelle consists of two rows 

 of basal granules whose ciliary rootlets fuse into a single plate, the basal 

 lamella. Each longitudinal fibril of the dorsal and ventral surfaces, with 

 the exception of those that merge with one another, is connected at the 

 adoral zone with the basal lamella of a membranelle. The basal lamella 

 is connected with the adoral fibril by fibril running across the peristomal 

 groove. The adoral fibril starts at the anterior tip and follows the course 

 of the inner border of the adoral zone. The peristomal fibril is continued 

 beyond the end of the adoral zone on the wall of the funnel and ends 

 in a ganglion-like body on the left wall of the ventral lobe. From this 

 motorium arise several fibrils — the adoral fibril, which follows the course 



