99 



protractile; hookB absent; suckers globular, near the apical portion of the head, 80 

 to 160/tin 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 proglottids; 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/i in diameter, yellowish ia color, 

 may be radially striated; inner membrane 24 by 20/j to 40 by 35/i in diameter, with 

 mammillate projection at each pole often not apparent; between outer and inner 

 membranes a prominent third layer of albuminous substance, often appearing as two 

 delicate smooth membranes, with intervening space filled by a granular coagulum; 

 embryonal hooks 11 to 16^ in length. 



Habitat. — Adults in small intestine of brown or Norway, rat ( Mvis decumanus), black 

 rat (M. rattus), house mouse (M. musculus), Egyptian or roof rat (Jf. rattus alexan- 



v.Jf. s.g. if^yKeX 



Fig. 27. — Male and female organs of H. diminuta: c. p., cirrus pouch; g. p., genital pore; ou., ovary; rec. 

 sem., receptaculum seminis; s. ff., shell gland; (., testiculae; ai., uterus; ua^., vagina; v. 5e/., vas deferens; 

 V. ef., vas eflerens; ties, sem., vesicula seminalis; y. g., yolk gland. Enlarged. (After Zschokke, 1889, 

 pi. 2, fig. 22.) 



Fig. 28.— Gravid segment of H. diminuta. Enlarged. (After 

 Grassi, 1881, pi. 11, fig. IS.) 



Fig. 29.— Egg of H. diminuta 

 from man. Greatly enlarged. 

 (After Bizzozero, 1889a, pi. 4, 

 fig- g".) 



drinus), wood or field mouse {M. sylvaticus), Rhipidomys pyrrhorhinua [according to 

 Linstow, 1878a, 23], and man (Homo sapiens). 



land, 1859; H. {Lepidotrias)Jlavopunctata 'WeinlB.nd, 1861; T. Jiavomaculata Leuckait, 

 1863; T. "Jlavopuncta" Cobbold, 1864 (misprint); T. "flaviopunctata" Vogt, 1878 

 (misprint); T. "flavopunhtata" Stein, 1882; T. varesina E. Parona, 1884; T. minima 

 Grassi, 1886; T. " septocephala" Fenoncito and Aholdi, 1888 (mispiiat) ; Symenolepis 

 diminuta (Rudolphi, 1819) Blanchard, 1891; " Eym^nolepsis" flavopunctata of Osier, 

 1895, and other authors (misprint); T. "varerina" Huber, 1896 (misprint for T. vare- 

 sina); T. "flavapunctata" Simon, 1896 (misprint); T. "leptocefala" Previtera, 1900; 

 T. " ceptocephala" Lussana and Romaro [? date] (misprint); Teniajlavopunetata (Wein- 

 land, 1858) Packard, 1900. 



