
SYNOPSES OF NORTH-AMERICAN 
INVERTEBRATES. 
XII. Tue TREMATODES. 
PART II.— THE ASPIDOCOTYLEA AND THE MALACOCOTYLEA, 
OR DIGENETIC FORMS (continued). 
H. S. PRATT. 
KEY ro THE SPECIES OF NORTH—AMERICAN ASPIDOCOTYLEA AND 
MALACOCOTYLEA, SO FAR AS DESCRIBED, 
GENUS STICHOCOTYLE. 
Larva found in Nephrops norwegicus and Homarus americanus : length 
3-7 mm., with 7-22 suckers. Adult in Raja clavata: length 17-105 mm., 
with 20-27 suckers . S. nephropis Cunn. (Fig. 2) (62, 68) 
GENUS COTYLASPIS. 
Body white or pinkish: in various species of Unio and Anodonta 
C. insignis Leidy (Fig. 5) (22, 23, 73, 16, 17) 
GENUS COTYLOGASTER. 
Body elongate; anterior portion of body terminated by a five-lobed disk 
surrounding the mouth; sucking disk with 132-144 depressions; marginal 
sense organs present; from dorsal surface near posterior end rises a broad 
conical elevation, at base of which is excretory pore; length 8 mm.: in 
gut of sheepshead in Minnesota . . . . - C. occidentalis Nick. (66) 
GENUS ASPIDOGASTER. 
Number of depressions about 64; sucking disk elliptical, covering two- 
thirds of the body : in pericardium, liver, and kidney of Unio and Anodonta 
A. conchicola v. Baer (Fig. 7) (20, 22, 23, 16, 17, 78) 
GENUS PARAMPHISTOMUM. 
a,. Body ovoid or elliptical. 
4,. Acetabulum large; testes 2, lobate, in median line; 12 mm. long, 
5 mm. wide: in intestine of Manatus : 
P. fabaceum Dies. (32) 
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