No. 6.] THE CESTODE MONIEZIA EXPANSA. 283 



the left. On the dorsal surface the furrows appear normal. 

 Relations at the two edges are apparently normal, and the 

 genital organs appear normal in all respects. 



The relations of the inter-proglottidal glands to the abnor- 

 mal furrows are interesting. Those portions of the furrow 

 which run transversely show the glands in their usual position, 

 but there are none in the region where the furrow departs from 

 its transverse course. Two of the glands (gl} in the partial 

 segment d present very peculiar relations to the furrow. Here 

 the furrow bends posteriorly, but the last two glands appear 

 at some little distance anterior to it and almost in line with 

 the others and are connected with the furrow by distinct ducts 

 of considerable length. In the posterior region of the curve 

 two of the glands lie posterior to the furrow as it curves for- 

 ward, but these open directly. The relation of the glands to 

 this curved furrow affords further evidence in favor of the 

 conclusion that the curved furrows do not always coincide 

 with segmental boundaries. Here the glands do not follow 

 the furrow in this curve, but lie at some distance from it and 

 are entirely absent from that portion which departs farthest 

 from the normal condition. It appears as if the glands fol- 

 low the line of the real boundary, while the furrow does not. 

 Nevertheless, as the presence of the ducts indicates, the glands 

 tend to open in the furrow. 



Figure 39. 



The series of abnormalities occurring in the three segments 

 represented here is in some respects the most peculiar that I 

 have found in this species. The figure is a ventral view. 



In the segment a the relations on the right are normal, but 

 on the left there appears on the dorsal surface the anterior end 

 of a spiral, the remainder of which is not drawn, as it makes 

 only one turn and is similar to others already discussed. The 

 ducts of the organs a' extend to the surface in accordance with 

 the relations on the dorsal surface and thus open at a point on 

 the edge which is dorsally a part of a, but ventrally in another 

 proglottid. 



