PARASITIC ROUND WORMS 527 



36 (35) No trifid cervical papilla present. 



Acuaria ardeae (A. J. Smith) 1908. 



Male unknown. Female 17 by 0.7 mm. Two lateral lips, each with double papillae. From 

 base of each lip two prominent submedian ridges on surface extend posteriad nearly to center of 

 body, then dorsad and ventrad respectively to join similar lines on opposite side. Esophagus 

 2 mm. long, in two sections: anterior narrow region 0.8 by 0.05 to 0.09 mm., posterior wider 

 region 1.2 by 0.2 mm. Anus 0.35 from tip of tail which is bent strongly dorsad. Vulva near 

 center of body; no eggs developed. 



In Ardea herodias. Described originally as Dispharagns ardeae by A. J. Smith. 



37 (30) Preanal papillae in male numerous, grouped in pairs and stalked. 



Family THELAZIIDAE Railliet 1916. 



Head naked or provided with cuticular thickenings or helmet-like covering. Mouth with 

 2 to 6 very small lips or without any, followed by a long vestibule or a short buccal capsule. 

 Esophagus composed of two distinct regions. Males with or without lateral alae in caudal 

 region, with a linear row of numerous preanal papillae, often paired; postanal papillae less 

 numerous; 2 spicules, almost always unequal. Female with double uterus; vulva variable 

 in location. Oviparous or viviparous. 



Only genus in North American aquatic hosts. 



Cystidicola Fischer 1797 . . 38 

 No valid record exists for the European C. farionis in North America. 



38 (39) In air-bladder of salmonid fishes. 



Cystidicola stigmatura (Leidy) 1886. 



Length: male, 12 to 25 mm.; female, 20 to 40 mm. Width: male, 0.25 mm.; female, 0.45 

 mm. Mouth circular with 2 minute lateral teeth. Buccal capsule tubular, 0.12 to 0.24 mm. 

 long. Anterior region of pharynx 0.5 to 0.6 mm. by 0.054 mm., posterior region 2.1 to 2.4 



mm. by o.i mm. Male with 

 narrow lateral membranes on 

 caudal end ; 5 pairs of single 

 postanal papillae, 9 pairs of 

 double preanal papillae. Two 

 unlike spicules; one slender 0.8 

 to 0.9 mm. long, o.oi mm. wide; 

 other trowel-shaped, 0.16 mm. 

 FIG. 820. Cystidicola stigmatura Anterior end of female. X 85- l ong ai g mm . ^de. Female 

 (After Ward and Magath.) sexual pore near center of body . 



uterus with anterior and posterior branches both well developed and symmetrical. Ova thin 

 shelled, containing developed embryo when laid, 44 by 27 //. 



In air-bladder of Great Lakes trout, white fish, and lake herring. Lake Erie, Lake St. 

 Clair, Lake Michigan, Lake Ontario (Leidy). 



In half or more of fish examined. Reported by Wright as Ancyracanthus cystidicola and by 

 Leidy as Filaria stigmatura. 



39 (38) In heart of white fish Cystidicola serrata (Wright) 1879. 



Length n mm. With several small teeth around anterior end instead of two as in former 

 species. Only a single specimen found by Ramsay Wright at Toronto. Perhaps an imma- 

 ture specimen, either migrating in blood stream, or accidentally introduced into this peculiar 

 location. 



40 (29) Male with conspicuous ventral ridges near posterior end; preanal 



papillae absent or inconspicuous. Body spinous. 



Spinitectus Fourment 1883. 



Mouth without lips or papillae. Except at extreme tip the body is encircled in the ante- 

 rior half or more by rows of spines pointing backward. The ventral surface in the male carries 

 several parallel series of rugosities just anterior to the anus. 



Representative North American species. 



Spinitectus gracilis Ward and Magath. 



Mature female 17 to 19 mm. long, 0.14 broad; male 12 mm. long, 0.075 rnm. broad. About 

 130 rows of spines with 40 to 50 in each row. Anterior tip free from spines for 0.12 wn- in 



