5^8 



FRESH-WATER BIOLOGY 



female, o.i in male. Vulva one-fourth total length from caudal tip. Spicules two, large, 

 heavy, unequal. Ova 41 by 24 n, thick- waUed. 

 In intestine of black crappie, sheepshead, and white bass at Fairport, Iowa. Abundant. 



Fig. 821. Spinitectus gracilis. Anterior end of female. X 220. (After Ward and Magath.) 



41 (28) Posterior end in female modified to form a sort of sucker by which 

 the parasite is attached to the stomach wall. 



Hedruris Nitzsch 1821. 



Head with 4 lips: 2 lateral, slender, each with 2 papillae; 2 median, thinner, overlapping 

 laterals almost completely. Vulva near anus. Tail of female modified to form with included 

 spine, the caudal tip, an adhesive organ or sucker. Eggs elhptical, with lid-like areas at both 

 pointed poles, contain developed embryos. Male spirally wound around female. Tail strongly 

 compressed laterally: 6 pairs postanal papillae, i pair just preanal. Spicules 2, similar, very 

 short, apparently grown together. 



Tj^e species Hedruris androphora Nitzsch 1821. 



RefX)rted from Amhlystoma mexicana and Nanemys guttata by Stiles and HassaU. The form 

 described by Leidy in 1851 as Synpleda pendula certainly belongs in this genus if not in this 

 species. 



Also recorded Hedruris siredonis Baird 1858. 



In British Museum collection. From "stomach of Siredon mexicanus from Mexico." Male 

 not found. 



42 (27) Anterior end provided with heavy, lateral, valve-shaped lips. 



43 



43 (48) Lips red or brown, very conspicuous. Esophagus with two well 

 differentiated, distinctly separated regions. No preanal 

 sucker in male. 



Family Camallanidae RaiUiet and Henry 1915 . . 44 



Body nearly cylindrical, with heavy oral armature having the appearance of a bivalve shell, 

 which is really 2 thick, lateral, valve-hke lips probably functioning as jaws and not a buccal cap- 

 sule. Each valve marked by longitudinal ridges terminating at the inner margin of the mouth 

 in minute teeth. Mouth an elongated oval; inner opening of oral cavity to esophagus round, 

 encircled by hea\y basal ring of chitin. Several (2 to 4) hea\y chitinous rods diverge from 

 common center at each side of capsule along sides of body beneath cuticula, forming a fork 

 or "trident." 



Esophagus bipartite, anterior region muscular, club-shaped; posterior dark, granular (gland- 

 ular?); valve to intestine. 



Tail of male surrounded by narrow, poorly developed caudal alae with stalked papillae. A 

 single spicule with accessory piece or two nearly equal spicules. Female sexual pore towards 

 center of body. Viviparous; embryos develop in Crustacea and insect larvae. 



Parasitic in aUmentary canal of fishes and reptiles. 



Single genus known Cawa//awM.y RaiUiet and Henry 191 5. 



These forms are often cited as Cucullanus and Dacnitis. RaiUiet and Henry have recently 

 cleared up the confusion previously existing in the group. 



