Trematodes and Cestodes 19 G-H 



"2 to 3 cm. in length by 0-8 mm. in width. 4 unarmed suckers, 22 to 

 27 hooks, 19 to 20/i in length, on the rostellum. Neck short, very slightly 

 narrower than the head. About 80 segments; posterior borders projecting, 

 last a little longer than wide. Reproductive openings very irregularly 

 alternating, one-fifth of length of segment from anterior edge. 20 to 25 

 testes, ellipsoidal, large, axis transverse, located in a little more than the 

 posterior one-third of the segment. Coils of vas deferens in anterior one- 

 third of segment. Two kinds of spines on cirrus; short and stout towards 

 the summit, fine and slender at the base. Ovary with two lateral wings in 

 middle third of segment. Vitelline glands immediately anterior to testes. 

 Vagina opens into a narrow, cylindrical genital cloaca, behind and on the 

 same horizontal plane as the cirrus. Receptaculum seminis between 

 ovarian wings and ahead of yolk gland, not very voluminous and scarcely 

 central. In Sturnus vulgaris." 



Nevertheless, the differences between the two forms seem to be sufficient to 

 warrant the erection even in the absence of the rostellar hooks of a new species, 

 the first of this genus, so far as I know, to be described from Passerella iliaca. 



Family II HYMENOLEPIDIDAE Railliet et Henry 1909 

 Subfamily I HYMENOLEPIDINAE Ransom 1909 

 Genus Hymenolepis Weinland 1858 



Subgenus Aploparaksis Clerc 1903 

 Aploparaksis elisae Skrjabin 1914, e.p 



1914: Aploparaksis elisae SKRJABIN : . . . . 1914: 451 



(Type host, Fuligula nyroca; Talass River, near Aulie-Ata, Turke- 

 stan.) 



Specific diagnosis. With the character of the genus. Medium-sized 

 cestodes with a length of 120 mm. by a maximum breadth of 1 4 mm. Rostellum 

 (half retracted) 30ju in diameter at base; bears ten hooks, each 25-9^ in length. 

 Anterior segments (where first uteri appear), 0-08 mm. in length by 0-60 to 

 0-64 in width; posterior (gravid), 0-12 mm. long by 0-93 to 1-4 wide; second 

 last proglottis, convex laterally and freed of most of its eggs, 0-20 mm. long by 

 0-48 wide. Posterior borders of all but the hindermost segments salient, giving 

 the strobila a fine saw-toothed appearance laterally. 



Genital pore situated slightly ahead of, at, or slightly behind the middle of 

 the margin of the segment. Opening of vagina immediately ventral to that of 

 cirrus and at the bottom of a very shallow, funnel-shaped genital atrium, 12^ in 

 dorsoventral diameter and lOju. in transverse diameter (depth). 



Testis median, spheroidal in shape, fills up the whole of the segment antero- 

 posteriorly, 0-10 to 0-12 mm. in length by 0-15 to 0-19 in width by 0-11 to 

 0-12 in depth. Testes are so large that those of consecutive proglottides push 

 by each other and hence often appear as two rows along the strobila. Outer 

 seminal vesicle oval or ellipsoidal in shape, dorsal to inner end of cirrus-sac, 

 0-110 mm. in transverse diameter (its length), 0-035 and 0-45 in dorsoventral 

 and longitudinal diameters, respectively. Width of proximal coils of vas 

 deferens, 90/*, length, 36/z. In young segments the cirrus-sac extends to the 

 median line; in ripe joints it occupies only one-quarter of the transverse diameter 

 of the strobila; 0-26 to 0-28 mm. in length by 0-023 to 0-027 in diameter. 

 Inner seminal vesicle, 0-172 mm. long by 0-018 in diameter. Cirrus unarmed, 

 0-110 to 0-125 mm. in length (within the sac). 



Most of the vagina is enlarged to form a very large seminal receptacle 

 which extends from just within the genital atrium to past the median line, 



