86 
Figs. 140 to 143. — Four different specimens of Sparganum mansoni: a., cross sections. ' Figs. 140 to 142 
natural size; fig. 143 x 2. (After Ijima & Murata, 1888a, figs. 1, 3, 4, 5.) 
The Proliferating Japanese Tapeworm Larva — SPARGANUM PROLIFERUM « 
(Ijima, 1905) Stiles, 1906. 
[Figs. 144 to 166.] 
Specific diagnosis. — Sparganum: Larva may attain 1 to 12 mm. in length and 2.5 
mm. in breadth; head narrower and more motile than posterior end, and may show 
an apical depression which, jierhaps, serves as sucker; no true suckers or other 
organs of attachment present. Calcareous corpuscles spherical or ellipsoidal, 7.5 to 
12 m in diameter, and situated in any part of body except head; irregularly dis- 
tributed reserve-food bodies present in older specimens, but they later undergo 
disintegration; genital organs not present; longitudinal muscles better developed than 
a Synonyms. — Plerocercoides prolifer Ijima, 1905; Plerocercus prolifer Ijima, 1905. 
Neither Plerocercoides (type bailleti ) nor Plerocercus is available in naming this species. 
Because of the remarkable reproduction of the larval stage, a new genus would prob- 
ably be justified, but there are some advantages in placing the worm, at least for the 
present, in the collective group Sparganum. 
Bibliography. — See Ijima, 1905. 
