13 
their breadth. Genital pores on the left margin, near anterior border of each seg- 
ment. Three testes in each segment; vas deferens enlarged to form a seminal vesicle 
within the cirrus pouch, while a seminal reservoir outside cirrus pouch is only 
slightly developed or absent. Gravid uterus occupies nearly the entire segment; wall 
of uterus with a few inconspicuous infoldings, forming incomplete j>artitions extend- 
ing into the cavity of the uterus. Eggs number 80 to 180 in each segment; oval or 
globular; two distinct membranes; outer membrane 30 to 60 ft in diameter; inner 
membrane 16 to 34 /< in diameter, presenting at each pole a more or less conspicuous 
mamillate projection, provided with filamentous appendages; embryonal hooks 10 
to 14 yu long. 
Habitat. — Small intestine of brown or Norway rat [Mus decuinanus)-, black rat 
{Musrattus)', dwarf field mouse {Mus minutus)] house mouse muscuhis); garden 
dormouse {Eliomys querchius); and man {Homo sapiem). 
Development. — The embryo is swallowed, and after hatching enters a villus of 
the small intestine, Avhere it transforms into a cercocystis, which in turn falls into 
the lumen of the intestine and becomes adult. 
Geographic distribu'^iox.— Egypt, England, Italy, Sicily, Russia, Germany, 
Servia, France, Austria, Denmark, Siam, Japan, Pennsylvania, District of Columbia, 
Maryland, South Carolina, Georgia, Texas, Brazil, Argentina. 
The Flavopunctate Tapeworm — HYMENOLEPIS DIMINUTA« (Rudolphi, 
1819) Blanchard, i8gi. 
Specific diagnosis. — Hymenolepls: Strobila 10 to 60 mm. in length, 2.5 to 4 
mm. in maximum breadth; composed of 800 to 1,300 segments. Head small, 
almost globular; 200 to 600 // in width; rostellum rudimentary, pyriform, only 
slightly protractile; hooks absent; suckers globular, near the apical portion of 
the head, 80 to 160 p in diameter. Neck usually short. Segments throughout 
strobila broader than long. Genital pores on left margin, near the junction of the 
anterior and middle thirds of each segment. Three testes in each segment; vas 
deferens dilates into a prominent seminal vesicle before entering the cirrus pouch, 
within which also is a vesicle. Gravid uterus occupies most of the proglottis; its 
cavity is subdivided into a large number of incompletely separated compartments 
filled with eggs. Eggs round or slightly oval ; outer membrane 54 to 86 u in diam- 
eter, yellowish in color, may be radially striated; inner membrane 24 by 20 p to 40 
by 35 p in diameter, with mamillate projection at each pole often not apparent; 
between outer and inner membranes a jirominent third layer of albuminous sub- 
stance, often appearing as two delicate smooth membranes, with intervening space 
filled by a granular coagulum; embryonal hooks 11 to 16 p in length. 
Habitat. — Adults in small intestine of brown or Norway rat {Mus decumanus); 
black rat (J/. rattus); house mouse {M. muscuhis)', Egyptian or roof rat {M. rattus 
alexandrinus) ; wood or field mouse {M. sylcaticus); Rhipidomys pyrrhorhinus 
[according to Linstow, 1878 a, p. 23]; and man {Homo saqnens). 
« Synonyms. — Tsenia diminuta Rudolphi, 1819; T. lep>tocephala Creplin, 1825; 
Hymenolepis flavopunctata Weinland, 1858; Taenia {Hymenolepis) Jiavopunctata Wein- 
land, 1859; H. {Lepidotrlas) davopunctata Weinland, 1861; T. Jiavomaculaia Leuckart, 
1863; T. ‘[davopuncta^^ Weinland of Cobbold, 1864 (misprint); T. ‘[daviopunctata” of 
Vogt, 1878 (misprint); T. ‘[davopunJdato” of Stein, 1882 (misprint); T varesina E. 
Parona, 1884; T. minima Grassi, 1886; T. “septocephala^' of Perroncito & Airoldi, 1888 
(misprint); Hymenolepis diminuta (Rudolphi, 1819) Blanchard, 1891; “Hymenolep- 
sis'^ flavopunctata of Osier, 1895, and other authors (misprint); T. ^‘varerina'^ Parona 
of Huber, 1896 (misprint for T. varesina)', T. ‘flavapunctata of Simon, 1896 (mis- 
print) ; T. ^deptocefala" Previtera, 1900 (misprint); T. ceptocephala Lussana &Romaro 
[?date] (misprint); Tenia flavopunctata'’ of Packard, 1900. 
