No. 404.] MWORTH-AMERICAN INVERTEBRATES. 659 
long, 5 mm. wide ; from gills and under the opercles of sturgeon 
(Woods Holl, Linton, etc.) . . N. elongata Nitzsch (Fig. 4) 
4, Body linear, contracted postiin i very small ; anterior portion papil- 
lose ; sucking disk not globose ; 1.9 mm. long, .5 mm. wide: from 
mod (Woods Hol. 5 . . 5. . LV. papillosa Linton 
GENUS ACANTHOCOTYLE. 
Body linear; anterior end blunt with a pair of glands and without 
anterior suckers ; sucking disk large, circular, as wide as the body, with 
thirty-four radial rows of hooks; about thirty-seven testes ; 5 mm. long, 
1.2 mm. wide : on skin of skate (Cape Cod) . A. verrilli Goto (Fig. 10) 
GENUS DIONCHUS. 
Intestine bifurcate, distal ends fused ; anterior end of body triangular, 
with two groups of glands; genital pore minute, on left side of ventral 
surface, near mouth ; 2 mm. long, .5 mm. wide (Newport) 
D. agassizi Goto (Fig. 18) 
GENUS POLYSTOMA. 
& 
- 
. Posterior disk-like region attached to body between the two anterior 
pairs of suckers. 
/,. Body elongate, lanceolate; disk wider than body; three pairs 
minute hooks between anterior pair of suckers, one large and 
two small pairs between posterior pair of suckers ; 6 mm. long : 
in the nose of the food terrapin . . P, coronatum Leidy 
4,. Body broad, tapering forward; disk kgd; testis a large 
slightly lobed body in center of body ; three pairs small hooks 
between anterior pair of suckers, and three pairs of small and 
one pair large hooks between posterior pair of suckers ; intestine 
bifurcate, unbranched ; 1.5 mm. long, 1 mm. wide : from urinary 
bladder of Kinosternon pennsylvanicum 
P. hassalli, Goto (Fig. 23) 
. Posterior disk-like region, attached at its anterior end to body ; body 
elliptical ; intestine bifurcate, unbranched ; penis provided with six- 
teen spines, alternately small and large; 2.5 mm. long, 1 mm. wide : 
in urinary bladder of musk turtle (Avomochelys odoratus) 
P. oblongum R. R. Wr. 
& 
to 
GENUS SPYRANURA. 
Body elongate, contracted anteriorly and posteriorly just before disk, 
which is wider than body and bears two large suckers ; intestine bifurcate, 
unbranched ; testes numerous; 4 mm. long, .6 mm. wide: on skin of 
Necturus , . o | o oc od MTM R Wr (Fw. 22) 
