NO. 2258 TAENIOID CESTODES OF DOGS AND CATS— HALL. 



29 



of the blade. The suckers are situated at the angles of the head. 

 They are relativel}^ large, about 810 ia in the longest diameter, and 

 are set rather close to one another. The neck is distinct or indistinct, 

 according to the state of contraction, and is approximately 500 ^ 

 long from the posterior margin of the suckers to the first distinct evi- 

 dence of segmentation. The strobila is from 75 cm, to 5 meters long, 

 the average strobila being 2 meters long and consisting of 650 to 700 

 very thick segments. In such a strobila the short wide segments at 

 the anterior portion of the strobila gradually become larger, but the 

 mature segments are also wider than long. Mature segments begin 



about 50 cm. behind the head about 

 the two hundred and seventy-fifth to 

 the three hundredth segment. These 

 segments are about half as long as 

 wide, being 3.78 mm. long and 7.5 

 mm. wide. These are followed bv 

 about 50 quadratic segments in which 

 the uterus branches are formine 

 and the genital glands undergoing 

 atrophy. Gravid segments begin 

 about the five hundred and eightieth 

 to the six hundred and tenth seer- 

 ment, and are longer than wide, be- 

 ing 10 to 15 mm. long and 4 to 5 mm. 

 wide. The lateral margins of the 

 strobila are smooth and without ser- 

 ration, but the posterior margin of 

 each segment is continued posteriorly 

 over the anterior portion of the suc- 

 ceeding segment, forming an envel- 

 opiii-g cuff. In the gravid segments 

 there is a tendency, characteristic of 

 the species, to show a median longi- 

 tudinal furrow on the dorsal and 

 ventral surfaces, the furrow terminating posteriorly in a notch. The 

 genital papillae are near the middle of the lateral margins of the 

 segments and are not at all prominent. The calcareous corpuscles 

 are usually oval, with a maximum diameter of 20 [l. The longitudi- 

 nal excretory canals are about 700 p. from the lateral margin of the 



segment. 



Mole genitalia.— There are about 600 to 700 relatively small testes 

 (fig. 35). which are very thickly distributed in one plane and sepa- 

 rated bv a continuous sheet of parenchyma from the ovary and the 

 vitelline gland. The testes extend close to the median stem of the 

 uterus and the vas deferens and vagina, leaving little clear space 



Fio. 34.— Taenia hydatigena 



SMALL HOOKS. 



Laege and 



