
908 THE AMERICAN NATURALIST. | [Vor. XXXVI. 
€» Male and anterior portion of female filiform; posterior 
portion of female swollen and reniform: in the mouth 
and gill cleftsof fish, living in cysts, a male and a female 
being in a cyst . Keellikeria Cob. (Fig. 108) (86) 
4,. Two suckers present, the oral sucker and the ventral acetabulum, 
together with a large, a constructed ventral projection, or disk, 
of use in attachment š i amily IV. Holostomidz _ 
6,. Body circular, not made up of two portions; acetabulum usually 
„covered by a large disklike structure which possesses a large 
cavity extending itself into a longitudinal groove: in intestine of 
birds. . Cyathocotyle Mühl. (Fig. 109) (60) 
4, Body head acd seid up of two distinct portions, the anterior 
portion being usually flattened and containing the acetabulum 
and the special organ of attachment. 
cı» Lateral edges of anterior portion not bent ventrally ; special 
organ of attachment an elongated depression lined with 
papilla. ... , («1a Babfamily H. BORET 
d,. A row of subdere suckers on hinder part of body: i 
intestine of the alligator 
Polycotyle Will.-S. (Fig. 110) (95) 
d,. No dorsal suckers: in intestine of reptiles and birds 
Diplostomum v. Nord. (Fig. 111) (3) 
Cy Lateral edges of anterior portion bent ventrally. 
d,. Anterior portion trough-shaped ; special organ of attach- 
ment an elongated elevation, which may project over the 
acetabulum. 
é,- In birds and land mammals 
Hemistomum Dies. (Fig. 112) (3) 
£, In Delphinus .... . . Braunina Heider (12) 
. Lateral edges of anterior " natis meet and fuse mid- 
ventrally, making this part of the body cup-shaped; spe 
cial organ of attachment a conical projection: usually 
in birds . . . . . Holostomum Nit. (Fig. 113) (3) 
a, But one sucker present and no other organ of attachment. 
ó, Mouth in the middle of the ventral body surface; sucker at 
anterior end; intestine not bifurcate; genital and excretory 
pores at posterior end: in the intestine of fish 
Gasterostomum v. Sieb. (Fig. 114) (33) 
6,. Mouth at anterior end, sucker oral. 3 
€, Worms found in pairs in cysts on the gills, outer surface, or 1n 
the mouth of fish; intestine often rudimentary or wanting 
Family VI. Didymozoónidze 
d,. Anterior portion of body slender and cylindrical, posterior 
portion thick and cylindrical, or reniform 
Didymozoón Tasch. (Fig. 115) (3) 
A 

