14 
Superfamily DIBOTHRIOCEPHALOIDEA . a 
Ordinal diagnosis. — Cestodci: Scolex armed or unarmed, with two groove-like 
suckers, situated dorsally and ventrally; they are usually not highly developed, but 
in some cases are considerably modified by development of their walls, or by more 
or less coalescence of their margins; or they may unite to form a single apical sucker, 
or may become rudimentary, their function being performed by an unpaired apical 
sucker; in some cases a pseudoscolex may form. Xeck present or absent. External 
segmentation present or absent. Three genital pores present; uterine pore is always 
on one of the surfaces; the vaginal and cirrus pores may be on the same surface as 
the uterine or on the opposite surface or marginal. Genital organs usually single, 
rarely double. Their development progresses from anterior end posteriorly, but 
does not pass the mature stage into an atrophying stage. Testicles numerous, situated 
in two more or less separated lateral fields in the medullary layer; vas deferens 
always highly developed, usually forming a coil. Ovary distinctly or indistinctly 
bipartite, situated in distal portion of segment, usually median in forms with single 
series of genitalia; in forms with double series, submedian; in forms with lateral 
pores, on side of median line toward the pore. “ Schluekorgan” always present. 
Vitellogene glands with numerous follicles, situated in two, more or less separated 
lateral fields, nearly always dorsal and ventral, and usually in cortical layers. Eggs 
quite similar to t’ o e of Fasciola , but not always with operculum. 
Type family. — Di '>othriocephalidx. 
This superfamily maybe divided into two families ( Dibothriocephalidx and Ptycho- 
bothriidas), only one of which furnishes parasites to man, namely: 
Family DIBOTHRIOCEPHALIDiEF Luehe, 1S99. emend. Braun, 
1903. 
Family Diagnosis. — Dibothriocephaloidea (p. 14): Uterus forms a rosette. Eggs 
with operculum. 
Type genus. — Dibothriocephalus Luehe, 1899. 
This family is divided into 4 subfamilies ( Tricuspidariinx , Dibothriocephalinse, Ligu- 
linx , and Cyathocephalinae) , only one of which is represented among the intestinal 
parasites of man, namely: 
Subfamily DIBOTHRIOCEPHALIXLE Luehe, 1899. 
Subfamily diagnosis. — Dibothriocephalidx (p. 14): Scolex unarmed; suckers either 
two small grooves (one dorsal and one ventral) or two funnel-shaped organs with 
highly developed borders, or by eoalesence of their borders changed to sucker-tubes, 
or rudimentary and then replaced by an apical sucker. Xeck present or absent. 
External segmentation complete. Genital organs single or double. Genital pores 
ventral, median or submedian; cirrus, vagina, and uterine pores in a longitudinal 
row, in order named; genital atrium, into which cirrus and vagina open, is provided 
with numerous papillae. Ovary ventral and shell gland dorsal, always median in 
forms with single sets of pores. Vitellogene follicles always in cortical layer. Vas 
deferens very sinuous, running dorsally and changing to a globular or pyriform 
vesicula seminalis before opening into the cirrus pouch. Testicles in the medullary 
layer, for the greater part outside of the longitudinal bands. The vagina, extending 
ventrally, crosses the uterus near its pore, and widens to a receptaculum seminis (the 
limits of which are not distinctly defined distally, but distinctly defined proximally) 
opposite the narrow and short seminal canal which unites with the oviduct to form 
the fertilization canal. Uterus often forms a “rosette.” Eggs with operculum. 
« Synonym. — Pseudojjhyllidea Carus, 1863; Bothriocephaloidea Braun, 1903. 
& Synonym. — Bothriocephalidx of authors. 
