23 
Fig. 26. — Partially diagrammatic representation of a left set of main genital ducts as seen in ventral 
view: dr. , cirrus; dr. o., cirrus opening; dtg., yolk duct; ov., ovary; ovd., oviduct; sb, recepta- 
culum seminis; id., uterus; ut. o., uterine pore; rag., vagina; rag. o., vaginal opening; v. d., vas defer- 
ens. x 150. (After Ijima & Kurimoto, 1894a, fig. 10.) 
Fig. 27. An egg of D. grandis, taken from the uterus. x440. (After Ijima A Kurimoto, 1894a, fig. 9.) 
Medical significance. — Apparently similar to Dibothriocephalus 
latus. 
Superfamily T2ENI0IDEA. « 
Superfamily diagnosis. — Cestoda: Scolex with four cup-shaped suckers; between 
these may be an apical rostellum of various forms; suckers and rostellum may be 
armed with hooks or unarmed. In exceptional cases a pseudoscolex develops. 
Neck present or absent. Segmentation nearly always complete; mature segments 
usually do not escape until completely developed. Uterus without special pore. 
Cirrus and vagina usually open on margin, exceptionally on ventral surface. Geni- 
tal organs usually in single series; in some cases in double series, complete or incom- 
plete. Testicles in medullary layer, usually numerous. Ovary more or less bilobed. 
Vitellogene gland usually single, and distal of ovary at distal margin of the segment, 
seldom anterior of ovary; shell-gland between ovary and vitellogene gland. Eggs 
without operculum; onchosphere with one or several membranes. Bladder worm 
stage in vertebrates or in invertebrates. Adults in intestine of vertebrates, especially 
mammals 
Type and only family. — Txniidx. 
Family 'IFFXIIDiE 6 Ludwig, 1886. 
Family diagnosis. — Same as diagnosis of superfamily Tsenioidea. 
This family is divided into the subfamilies Mesocestoidinx, Acoleinx, Amabiliinx , 
Tetrabotliriinx, Anoplocephalinx, Dipylidiinx, Davciineinx, and Txniinx; three of these 
( Dipylidiinx , Davciineinx, and Txniinx, for key see p. 11) are represented among 
the parasites of man. 
Subfamily TvEXIIXAU Stiles, 1896. 
Subfamily diagnosis. — Txniidx : Usually large species; gravid segments usually 
considerably longer than broad. Scolex with rostellum and usually with double row 
a Synon ym. — Cycloph yllidea. 
b Synonym. — Txniadx. 
c Synonyms. — Txniea Goldberg, 1855a; Cystotxnix Claus, 1876; Txnianx Railliet, 
1896. 
