No. 5 meserve: monogenetic trematodes 67 



suckers (fig. 76) composed of eleven pieces, central piece bifurcated 

 at distal end, relatively short, bluntly bifurcated at proximal end; 

 short piece placed horizontally distal to central piece and between 

 its bifurcation, concave distally; four pairs in lateral walls of suckers, 

 on each side a basal piece extending laterally from middle piece, 

 convex at posterior border, and three curved, attenuated pieces 

 pointing obliquely and distally toward mid-line of sucker, joining 

 basal pair of lateral pieces at distal end; slender bar across top with 

 beaded appearance, bending inward at center toward middle piece 

 and convex at anterior borders on both sides. Anterior suckers ellip- 

 tical, longer than broad, 0.068 to 0.072 mm. in length by 0.044 to 

 0.048 mm. in width, without membranous septa. Mouth subterminal, 

 ventral, close to anterior end. Pharynx bulb-shaped, longer than 

 wide, 0.044 to 0.056 mm. in length by 0.036 to 0.040 mm. in width. 

 Esophagus extremely long and slender, passing ventral to brain 

 swinging to left past genital pore and swinging back again to mid- 

 line just posterior to genital pore, bifurcating posterior to genital 

 pore slightly anterior to level of vaginal opening. Intestinal limbs 

 slender with lateral branches, extend to haptor, not united posteri- 

 orly. Brain as in Axine, a relatively great distance posterior to 

 pharynx almost half distance from anterior end to genital pore. 

 Testes large, smooth, broader than long, unlobed, sixty-two in num- 

 ber, extending from ovary almost to haptor. Vas deferens relatively 

 wide and winding, passing posteriorly to right of uterus. Cirrus at 

 base of genital atrium, strongly muscular, cup-shaped, broader than 

 long with open end of cup pointing anteriorly, upper rim has circle 

 of fourteen strong curved spines, with points directed posteriorly 

 and toward center of cup, 0.014 to 0.020 mm. in length. Genital 

 pore anterior to bifurcation of esophagus. Genital atrium (fig. 78) 

 with four groups of spines, a complete circle near the genital pore, 

 with sharp recurved points directed away from center of circle, 

 0.016 mm. in length; two pairs of ten spines each on each side of 

 circle around genital pore, 0.020 to 0.024 mm. in length, bending 

 posteriorly from their base and then bending slightly anteriorly with 

 sharp points forming two parallel rows on each side of the genital 

 atrium; a posterior group attached to cirrus described above. Vagina 

 opens dorsally on right side at extreme right edge of worm slightly 

 posterior to level of bifurcation of esophagus. Vaginal spine (fig. 

 77) imbedded in wall of vagina at distal end extending out of vagi- 



