No. s-] THE CESTODE MONIEZIA EXPANSA. 247 



left edge than at the right and is very short in the middle region, 

 and especially just to the left of it, in consequence of the bent 

 course of the furrows bounding it anteriorly. At the right the 

 two furrows between c and d end on the surface in the region of 

 the ovaries, so that the right edge is undivided. At the left the 

 furrows end very near to the edge, but do not reach it. The 

 organs of the right side in c are normal ; in d, however, they are 

 rudimentary, consisting of a small imperfect ovary, o., vitellarium, 

 vt. t and a small closed and empty seminal receptacle, s.r., and, 

 entirely unconnected with these, a pore at the edge. No male 

 organs except the cirrus appear. The absence of male ducts is 

 perhaps due to the fact that this region of the segment d is 

 shorter dorsally than ventrally, in consequence of the peculiar 

 arrangement of furrows anterior to it. The pore of d is approxi- 

 mated to the pore in c, apparently because the furrows do not 

 reach the edge. At the left edge d is of nearly normal width, 

 though it narrows rapidly from the edge inward. Corresponding 

 to its size the set of organs is of about normal size, like the left 

 organs in c. These two sets open by distinct pores, which are, 

 however, approximated. 



The furrows anterior to d are very irregular. From the left 

 edge they extend slightly posteriorly, thus almost separating d 

 into two parts, then bend forward again and on the right end in 

 a peculiar manner. The ventral furrow does not reach the right 

 edge, but bends anteriorly and back upon itself, and ends on 

 the surface. From the right edge the other portion of the fur- 

 row extends inward for a short distance, then curves back upon 

 itself and ends. In the concavity of the curve near f a short 

 isolated furrow appears. The furrow on the dorsal surface bends 

 further anteriorly as it approaches the right edge and finally ends 

 on the surface before reaching it. Posterior to this furrow lies 

 another partial furrow corresponding to the right portion of the 

 ventral furrow. It does not, however, bend back upon itself, 

 but extends some distance to the left and then ends free on the 

 surface. Thus a small region, /, is incompletely marked off as 

 a partial segment on the dorsal surface, but ventrally the curved 

 furrows divide into two parts. No genital organs appear in /. 



The regions e and g are partially separated at the left by cor- 



