
894 THE AMERICAN NATURALIST. [VoL. XXXVI. 
f» Intestinal ceca without lateral projections. 
4,. Genital pore immediately behind acetabulum (but not on a papilla) ; 
body thick and egg-shaped ; intestinal coeca long; testes lobate, 
in same transverse plane; yolk glands very large; uterus very 
small, near acetabulum: in lungs of mammals 
Paragonimus Brn. (Fig. 17) (87) 
Zə Genital pore in front or at left side of acetabulum or, if behind, 
on a papilla. 
h,. Yolk glands dendritic, z.z., diffuse and not compact. 
z. Either a ring of spines or two spiny, retractile tentacles at 
anterior end. 
Jy- Testes in same transverse plane behind acetabulum; 
mouth surrounded by spines. 
k,. Testes and yolk glands near middle of body, which 
is broad Anoiktastoma Stoss. (Fig. 18) (44) 
&, Testes and ovary at extreme hinder end of body: 
in small intestine of birds and mammals 
Subfamily VIII. Centrocestine 
Z. Intestinal coca long; «esophagus wanting; 
testes and yolk gland large 
Centrocestus Lss. (Fig. 19) (44) 
4. Intestinal coeca short, not reaching acetabulum ; 
esophagus long; a dorsal lip over mouth; 
oral sucker prolonged posteriorly into a long, 
blind sac Ascocotyle Lss. (Fig. 20) (44) 
J» Testes one behind the other, not in same transverse 
plane. 
£,. Two spiny, retractile tentacles present, one on 
either side of mouth: in the opossum 
Rhopalias S. et H. (Fig. 21) (86, 7) 
&, Tentacles not present; body usually elongate and 
cylindrical; mouth surrounded by spines. 
4. Testes and ovary close together in extreme 
hinder end of body; oral sucker large and 
surrounded by a single row of spines: in rep- 
tiles and fish 
Acanthochasmus Lss. (Fig. 22) (44; 48) 
A. Testes and ovary usually not all close together 
and not in extreme hinder part of body, 
although in posterior half. 
m, Intestinal coeca do not reach to end of 
body and not of equal length; testes 
elongate ; mouth surrounded by a single 
row of spines: in intestine of fish 
Subfamily VII. Anisocceline 

