526 



FRESH-WATER BIOLOGY 



32 (33) Mouth without lips. 



FIG. 818. Haplonmea im- 

 mutatum. Anterior end show- 

 ing lateral alae. X 22. (After 

 Ward and Magath.) 



Male without caudal alae. 



Haplonema Ward and Magath. 



Anterior end flexed or coiled, provided with lateral alae. 



Esophagus muscular, without bulb, divided into two regions by 

 partition near center. Posterior end of male without bursa, with 

 two pairs of preanal papillae and three pairs of postanals. 

 Spicules two, equal. Vulva near center of body; ovary double, 

 laid in transverse loops near anterior and posterior ends. Ovipar- 

 ous. 



Only North American species. 



Haplonema immutatum Ward and Magath. 



Body moderately robust. Males 10 mm. long, 0.2 mm. broad; 

 females 15 mm. long, 0.31 mm. broad. No lips present; three 

 minute oral papillae. Esophagus divided about equally; anterior 

 and posterior regions not distinctly differentiated. Spicules 0.75 

 mm. long, 0.02 mm. broad, flat, ribbon-shaped. Eggs 65 by 45 ;u, 

 with moderately thick, smooth shell. Vulva five-eighths of 

 length from anterior tip. 



From intestine of Amia calva; Lake St. Clair, Michigan, and 

 Fairport, Iowa. 



33 (32) Mouth with well-developed lips. Male with caudal alae joined 



anteriorly across ventral surface of body. 



Physaloptera Rudolphi 1819. 



Mouth elongated dorsoventrally; bounded by 2 lateral, thick lips each canning a toothed 

 process and 2 broad submedian papillae. Caudal end of male with lateral alae and 10 pairs 

 of papillae, of wnich 4 are stalked and hi each ala, whereas 6 are sessile and on body. Spicules 

 2, unlike. Vulva in anterior region. Eggs very thick-shelled. 



Species reported in North America but not adequately known. 



Physaloptera constrida Leidy 1856. In stomach of Tropidonotus sipedon; Pennsylvania. 

 Also Physaloptera contorta Leidy 1856. In stomach of numerous turtles; Pennsylvania. 



34 (31) Anterior end with sinuous cuticular thickening or cervical frill. 



Subfamily ACUARHNAE Railliet, Henry, and Sisoff 1912. 



Anterior end provided with bands, epaulets, or similar ornaments. Mouth with two simple 

 lateral lips, pharynx and esophagus differentiated into two distinct regions. Caudal end of 

 male with lateral alae; four pairs of preanal papillae; postanals variable. Eggs with thick 

 shell, containing embryos when deposited. 



In digestive tract of birds. A numerous and varied group. 



Only genus yet recorded in North American aquatic hosts. 



Acuaria Bremser 1811 . . 35 



The cervical frill consists of two or four simple or complex loops draped from the tip of the 

 head back over the anterior region of the body. Vulva in posterior region. Two unequal 

 spicules. In esophagus, crop, or gizzard of birds. Often called Dispharagus in records. 



35 (36) With trifid cervical papilla. 



Acuaria triaenucha (Wright) 1879. 



Male unknown. Female 10 mm. long, 0.43 mm. broad. With cervical frill; 

 lateral loops 0.18 mm. from anterior end at top and extend 0.405 mm. posteriad. 

 Cervical papilla a trident spine, at base 0.06 mm. from end of frill, and 0.06 

 mm. long. Eggs 27 by 18 fj.. 



Single female taken from gizzard of Botaurus minor in Canada by R. Wright 

 and described as FUaria triaenucha. 



FlG. 819. Acuaria triaenucha. Cervical papilla. X 233. (After Wright.) 



