No. 5-J THE CESTODE MOXIEZIA EXPANSA. 219 



ventral surface. The pore opens into the genital cloaca, or 

 atrium, into which the male and female ducts also open. Fol- 

 lowing the female duct from this point, we find that it passes 

 inward, somewhat anteriorly and dorsal to both of the nephridial 

 tubes, then turns ventrally and posteriorly and opens into an 

 enlarged portion, the seminal receptacle, s.r. Just beyond the 

 seminal receptacle the ovary, o., appears in the form of a rosette. 

 The ovary consists of a mass of radiating branched tubules and 

 is somewhat flattened in the same plane as the proglottid. The 

 vitellarium, vt., lies somewhat ventral and usually posterior to 

 the ovary. At the stage shown in the figure the uterus does 

 not appear, but in later stages it consists of an anastomosing set 

 of tubes, which, after they receive the embryos, enlarge so as to 

 fill nearly the whole proglottid. From this description it is seen 

 that, although the ovary and vitellarium lie ventrally in the pro- 

 glottid, the outer or distal portion of the oviduct lies dorsally. 

 This point is important with regard to the relation of these 

 organs in abnormal segments. Following the male duct from 

 the atrium we find its terminal portion modified to form the 

 cirrus. Beyond this the vas deferens, v.d., follows the direction 

 of the oviduct anterior to it, but is much coiled. It also runs 

 dorsal to the nephridial tubes, but does not bend ventrally, as 

 does the oviduct. Anterior to the middle region of the ovary it 

 bends posteriorly and extends dorsal to the ovary toward the 

 middle of the segment. Beyond the bend it begins to branch 

 and soon breaks up into the fine tubules which connect with the 

 testes. These latter, t., lie scattered through the proglottid on 

 the dorsal side, but are more numerous in the posterior half. 

 They do not occur lateral to the nephridial tubes. Thus all of 

 the male organs are nearer to the dorsal than to the ventral 

 surface. 



DESCRIPTION OF THE ABNORMALITIES. 



All the figures except 7, 14, 15, 19, and 23 are taken from 

 a single chain. These five are taken from as many different 

 chains, and on comparing them with the other figures it becomes 

 evident that the abnormalities found so abundantly in the one speci- 

 men do occur, though less frequently, in very many individuals. 



