32 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 55. 



way into the liver, where it wanders around for a time, apparently 

 following the course of the blood vessels and causing a condition re- 

 sembling angioma. The embryos then develop in the liver to the 

 bladderworm, called Cysticercus tenuicoUis, and are either found ad- 

 herent to the capsule of the liver, or, more commonly, they slip into 

 the abdominal cavity and are commonly found surrounded by an 

 adventitious cyst attached to the mesenteries or omentum. On in- 

 gestion of these bladderworms by the primary host in eating the sec- 

 ondary host, as would be the case under natural conditions, the head 

 on the bladderworm attaches in the intestine and develops segments, 

 forming the strobilate worm. 



Of the hosts given above those not known to have been reported 

 previously are the Bharrel, Columbia deer, Odocolleus hemionus, 

 Rangifer novae-tem^ae., Alces alces^ Ovis mexicana, and Odocoileus 

 americanus. 



Writers c(;mmonly state that this species has from five to eight 

 lateral uterine branches, but I have often found 10 and believe a fair 

 count in some cases would show more. Comment has already been 

 made on the count of uterine branches in connection with Taenia 

 pisifonnis. 



Stiles and Hassall (1912) note that this tapeworm has been re- 

 ported for Felis catus {F. domestica). I have not found the refer- 

 ence in question and so am not in a position to comment on this. If it 

 were backed up by such evidence as there is to support the idea that 

 Taenia novella is really a dog tapeworm I would accept it. At pres- 

 ent, and for the purposes of this paper, the case will have to be re- 

 garded as not proven. 



The very striking median groove and its posterior notch on the 

 gravid segments is figured by Stiles (1898), but is not mentioned by 

 him. Deffke (IBDla) apparently overlooked it and I have not found 

 any mention of it. 



TAENIA OVIS (Cobbeld, 1869a) Ransom, 1913. 



Synonyms. — Cysticercus ovis Cobbold, 1869a/ Cysticercus ovi- 

 pariens Maddox, 1873a.; Cysticercus cellulose of Kuchenmeister, 

 1878, in Kuchenmeister and Ziirn, 1878-1881a (misdetermination) ; 

 Cysticercus tenuicoUis of Chatin, in Kailliet, 1885fir (misdetermina- 

 tion) ; Cysticercus oviparus Leuckart, 1886</. 



Specific diagnosis. — Taenia: The head is oblong, flattened in the 

 dorso- ventral direction and elongated along the transverse axis, and 

 is 800 {i, to 1.25 mm. wide. The rostellum is well developed, 375 to 

 430 p, in diameter, and bears a double crown of 24 to 36 hooks. The 

 large hooks (fig. 37) are 156 to 188 [/. long, the average being 173 p.. 

 The blade is of slight to moderate curvature; the handle is narrow, 

 with its dorsal and ventral margins, viewed from the side, approxi- 



