434 Bashford Dean Ts/lemorial Volume 



small cloacal apertures (U.S.l) for the urinary sinuses {U.S.) of which only the one on 

 the left side is shown. These apertures are situated close to the median line near the 

 posterior border of the cloaca. She states further that in the female the rectal aperture 

 (R.) is displaced to the right. The opening of the right oviduct (R.Ov.) is much larger 

 than the left {L.Ov.), and appears to crowd the latter anteriorly. This, perhaps, explains 

 the displacement of the rectal opening to the right. 



Text-figure 89. 

 Ventral view of cloaca, pelvis and pelvic fin cartilages of a female Chlamydoselachus. 



ah. p., abdominal pores; bf)., basipterygium; c!., cloaca; u.a., urethral aperture. 

 After Garman, 1885.2, PI. XII. 



ORGANS OF EXCRETION IN THE FEMALE 



The organs of excretion in the female Chlamydoselachus consist of a pair of meso' 

 nephroi or functional kidneys, numerous collecting tubules, a pair of mesonephric ducts 

 or Wolffian ducts, and a pair of urinary sinuses or functional bladders which are formed 

 by the enlargement of the posterior portions of the mesonephric ducts. In each of my 

 four specimens, the two urinary sinuses are entirely separate structures. 



The Mesonephroi. — In my four female specimens, the mesonephroi are a pair of 

 slender flattened organs (m. in Text 'figures 85 to 88) extending through about 87 per cent 

 of the total length of the body cavity (Tables II and III). Posteriorly, the mesonephroi 

 begin dorsal to the posterior margin of the rectal portion of the cloaca, save in specimen 

 No. IV where they begin as far back as the urethral orifice. Thus the mesonephroi do 

 not begin at the extreme posterior limit of the body cavity, which extends farther caudad 

 dorsally than it does ventrally. Dorsally, the body cavity extends as far back as the ex' 

 ternal openings of the abdominal pores, which are situated ventrally. The members of 



