10 PROCEEDINGS OF TEE NATIONAL MUSEUM. vol.55. 



to 420 [JL long. They have a blade of rather slight curvature; a 

 handle which maintains a generally straight direction except at its 

 distal extremity where it curves dorsad, and with a dorsal swelling 

 near its middle and another smaller dorsal SAvelling at its union with 

 the blade; and a guard with a tendency to bifid structure and pre- 

 senting in lateral view parallel borders proximally and a conical 

 termination distally. The small hooks (fig. o) are 250 to 270 \l long. 

 They have a blade of moderate curvature; the handle is straight 

 with a slight enlargement distally, the enlargement curved dorsad; 

 the guard enlarges just beyond its point of attachment, forming a 

 neck between the enlargement and the attachment, and then ter- 

 minates in a conical distal structure. The suckers are very promi- 

 nent, being set on the cylindrical head at an angle pointing forward 

 and outward. There is no neck, segmentation beginning directly 

 posterior of the suckers and the initial segments being as broad as 

 or broader than the head. The strobila attains a length of 15 to 

 60 cm. and a maximum width of 5 to 6 mm. The anterior segments 

 are very short, the following are cuneiform, and the terminal are 

 elongate, 8 to 10 mm. long by 5 to 6 mm. wide. Mature segments are 



wider than long and only terminal 

 gravid segments are longer than wide. 

 Calcareous corpuscles are numerous and 

 FIG. 4.-TAENIA TAENiAEFOKMis. DiA- ^^,^^|_ rj^YiQ parenchvma at times shows 



GRAM SHOWING THE TKANSVERSE EX- ^ " 



CEETORY CANAL ENCIRCLING EACH numcrous rather large areas that fail to 

 DORSAL CANAL. AFTER LovELAND, gtalu wlth Carmine. The genital papilla 



is in the middle of the lateral margin, 

 or anterior of the middle, is flat and inconspicuous, and is elongated 

 along the longitudinal axis of the strobila. The transverse excretory 

 canal is a single tube in the median portion of the strobila, but at its 

 union with the ventral canal it forms two branches which pass dor- 

 sally and ventrally and surround the dorsal excretory canal (fig. 

 4). The dorsal excretory canal i^ very sinuous and thick walled. 



Male genitalia (fig. 5). — The testes are numerous, oval or spherical 

 in shape, and are set close together in the lateral portions of the 

 median field close to the excretory canals. For the most part they 

 leave a clear field in the vicinity of the median stem of the uterus, 

 but may extend across this anteriorly; they press close to the field 

 occupied by the genital canals, or even invade it, and lie in contact 

 with the lateral portions of the ovaries and extend posterior of the 

 ovaries but not quite to the vitellarium. The vas deferens is very 

 much looped in a dense mass of closely approximated coils along the 

 transverse and longitudinal axis of the strobila, and apparently 

 originates at some distance from the median stem of the uterus on 

 the pore side of the segment. The cirrus pouch is slender, frequently 

 curved in gravid segments, and is difficult to observe in toto mounts. 



