22 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 55. 



Fig. 27.— Taenia bra- 

 CHYSOMA. Gravid 

 SEGMENT. En- 

 larged. After 

 Setti, 1899. 



in the middle of the strobila are rectangular, almost as long as wide, 

 and with the posterior angles less prominent and the strobila margin 

 smoother than anteriorly. The posterior segments are almost quad- 

 rate, the last two or three longer than wide. Occasionally the middle 

 segments are campanulate and a little longer than wide. Calcareous 

 corpuscles are especially abundant in the anterior portion of the 

 gtrobila. The small genital papilla is near the middle of segment. 

 It is most distinct in segments in the middle of the strobila. The 

 longitudinal excretory canals are about 500 y. from 

 the lateral margin of the segments. 



Male genitalia. — The aperture of the cirrus pouch 

 is at the base of a genital sinus 100 to 170 ^ long. 

 The median extremity of the cirrus pouch is about 

 at the plane of the longitudinal excretory vessels. 



Female genitalia. — The uterus (fig. 27) occupies 

 the median portion of the segments included be- 

 tween the longitudinal excretory canals. The me- 

 dian stem has 10 to 12 lateral branches on each side, 

 approximately perpendicular to the median stem, 

 and terminating distally in a variable number of 

 smaller branches of various sizes, shapes, and posi- 

 tions. Developed embryophores are only found in the last four or 

 five segments. The eggs are spherical and 32 p, in diameter. 

 Host. — Primary : Canis familiaris. Secondary : Unknown. 

 Location. — In intestine of primary host. 

 Locality. — Italy (Turin). 

 Life history. — Unknown. 



In a general way the circumstances indicate that this tapeworm, 

 like Taenia hrauni^ is also an accidental parasite of the dog. 



Setti's statement that the guard of the small hook is twisted so that 

 the lateral axis tends to lie in the plane of the blade and handle, has 

 been noted by Ransom (1913) with the following comment: "Setti 

 does not make it clear whether this twisted condition is invariably 

 present. The small hooks of Taenia hydatigena commonly present a 

 similar appearance after subjection to the pressure of a cover glass." 

 This point is well taken. Tapeworm hooks are flexible structures, 

 capable of considerable distortion under pressure or torsion, up to 

 the limit of flexibility, at which point, of course, breaking occurs. 



TAENIA PISIFORMIS (Bloch, 1780a) Gmelin, 1790a. 



Synonyms. — Vermis vesicularis pisiformis Bloch, 1780a; Hydati- 

 gena pisiformis (Bloch, 1780<2) Goeze, 1782a; Hydatigena utricu- 

 lenta Goeze, 1782a; Hydatigena cordata Batsch, 1786a; Hydatigena 

 utricularis Batsch, 1786a; Vesicaria pisiformis (Bloch, 1780a) 



