Trematodes and Cestodes 13 g-h 



Cuticula 5 to 6m in thickness, with neither hooks nor spines; sub-cuticula 

 25 to 40m. 



Ten to twenty sets of genitaUa, beginning 1 • 5 to 5 • mm. from the anterior 

 end. Strong tendency for the reproductive apertures to he all on one surface 

 of the strobila. Vagina opens behind the uterus. No papillae around the 

 female opening but the atrium is surrounded by a sphincter from 15 to 30m in 

 thickness. 



Testes in two lateral fields in the medulla of the anterior portion of the 

 proglottis, 60 to 115m in diameter. Coiled vas deferens antero-dorsal to the 

 cirrus-sac; no seminal vesicle before entering the cirrus-sac nor connective tissue 

 sack surrounding the whole duct. "Protruded cirrus 0-2 mm. in length by 0-12 

 in diameter at base. Cirrus-sac ovoid in shape, 0-20 to 0-26 mm. in length by 

 0-18 in diameter; no retractors connecting it with the dorsal body-wall; large 

 mass of glandular pigmented cells surrounding it dorsally and laterally. 



Vagina 12 to 18m in diameter; no sheath near its opening; receptaculum 

 seminis 35 to 75m in diameter. Spermiduct very short and narrow, 20 to 25 by 

 8 to 9m, respectively. Ovary tubulolobular, fan-shaped; wings extend laterally 

 and dorsally around the central connections of the female ducts; isthmus 

 prominent, 0-18 by 0-12 mm., ova in same, 12 to 15m in diameter. Oocapt 25 

 to 28m in diameter. Vitelline follicles continuous from proglottis to proglottis, 

 forming a layer 75 to 90m thick in the cortical parenchyma, 20 to 35 in transec- 

 tions. Shell-gland dorsal. Uterine rosette not surrounded by a muscular sac, 

 but the organ is enveloped proximally by numerous shell-glands. 



Eggs, 40 by 30m. 



Habitat. — The intestine of Cristivomer namaycush (Walbaum), the lake 

 trout; lake at Bernard harbour, C.A.E. Station 50gr, April, 1916. 



Only one specimen was found in the material from Station 50^, which other- 

 wise belonged to Ahoihrium crassum, Echinorhynchus salvelini and E. coregoni, 

 and, while undoubtedly belonging to C. americanus, was in many respects much 

 larger than any of those formerly studied. Consequently I submit the above 

 partly emended specific diagnosis to cover this case. The most striking anatom- 

 ical feature presented by this specimen is the comparatively large sphincter 

 muscle surrounding the aperture of the female genital atrium, a structure which 

 I have also been able to find on re-examination of the material upon which the 

 original description of the species was based. 



Genus II Bothrimonus Duvernoy 1842, e.p. Cooper 1919 

 Bothritnonus intermedius Cooper 1917, e.p. 



1917 : Bothrimonus intermedius Coopee 1917 : 35 



(Type host, Pseudopleuronedes americanus; St. Andrews, New Bruns- 

 wick) 

 1919: Bothrimonus intermedius Cooper 1919: 351 



Specific diagnosis. — With the characters of the genus. Small cestodes up 

 to 50 mm. in length and 2-8 in width. Scolex almost spherical, 0-48 to 0-72 

 mm. long, 0-50 to 0-84 wide and 0-60 to 1-0 thick. Bothria hemispherical, 

 their apertures ordinarily not fused to form a single terminal opening. Strobila 

 uniform in width from a short distance behind the scolex to the pbsterior end; 

 0-4 to 0-6 mm. in thickness; slightly more convex ventrally than dorsally. 



Cuticula, 5 to 10m in thickness. Nerve strands 12 to 20m in diameter; 

 each divides into two branches sagitally before entering the scolex; transverse 

 commissure diffuse. Four main excretory trunks in ripe proglottides, six farther 

 forward passing into the scolex; all in the medullary parenchyma. 



Reproductive organs begin 0-3 to 1-5 mm. from the scolex; up to 160 in 

 number. Weak sphincter around the common female cloaca. Vagina opens 

 close behind the uterine pore which is not quite in the median line. 



