275] NORTH AMERICAN MONOSTOMES 57 



compact, anterior to ovary. Laurer's canal and receptaculum seminis 

 were not observed by Barker. Eggs oval, twice as long as wide, 20 to 24/x 

 long 10 to 13/i wide. With long polar filament on each end about five 

 times as long as egg itself. 



HERONIMIDAE Ward 1917 



This family was created by Ward (1917) to hold the two aberrant genera 

 Heronimus MacCallum (1902) and Aorchis Barker and Parsons (1914). 

 Ward called attention to the close resemblance of the two forms and 

 suggested that they might prove to be identical. He characterized the 

 family as follows: "Moderate sized monostomes with thick, elongate, 

 soft body, slightly flattened, tapering toward both ends. Oral sucker weak; 

 pharynx large; esophagus short or absent; ceca simple, narrow, extending 

 to posterior tip but not united. Vitellaria compact, tubular. Uterus with 

 four longitudinal regions; genital pore ventral to oral sucker, near anterior 

 tip. Testis tubular, small; copulatory apparatus poorly developed. In 

 lungs of turtles, northern North America." 



One year later (1918) the same author restated the family diagnosis 

 with the following addition: " Vitellaria compact tubular, shaped like an 

 inverted V. Testes tubular, lobed or with short branches, united into a 

 V-shaped organ with the apex anteriad," and again stated that the two 

 forms probably belonged to the same genus. About a year later Stunkard 

 (1919) presented a paper in which he showed that the apparent difference 

 in the two forms was due largely to the partially diagrammatic figure of 

 MacCallum (1902) and to the discrepancies in the description of Barker 

 and Parsons (1914) and that the two forms are identical, thus not only 

 belonging to the same genus as suggested by Ward but representing a 

 single species, Heronimus chelydrae MacCallum. 



HERONIMUS CHELYDRAE W. G. MacCallum 1902 



Syn: Aorchis extensus Barker and Parsons 1914 

 Aorchis extensus Ward 1917 

 Monostoma sp. Stiles and Hassall 1894 



The genus was created by MacCallum (1902) to include worms collected 

 from the lungs and bronchi of Chelydra serpentina. The genus stands 

 according to MacCallum "in many respects far apart from the other 

 genera," especially in the position and nature of the genital opening, in the 

 complicated structure and course of the uterine tract, in the unusual 

 formation of the yolk glands, in the presence of but one testicle and in the 

 position of the excretory pore. The genus may be recognized by the 

 following diagnosis: Medium to large monostomes with semicyclidrical 

 body tapering slightly towards both ends; strongly muscular. Mouth 



