The Embryology of Chlamydoselachus 



56i 



Text-figure 18 

 Longitudinal section through cloaca and right oviduct of Chlamydoselachus, 

 three-fourths natural size. The dorsal side is uppermost. 



ab'p, abdominal pore; cl, cloaca; int, intestine; ov, oviduct; p, caecal pouch or rectal gland; ua, 



urethral aperture. 

 After Garman, 1885, Fig. 2, pi. XIX. 



The relative positions of the two openings as stated by Deinega make somewhat 

 clearer these openings as portrayed in Carman's drawing (Text-figure 18) of the cloaca of 

 his specimen. If one holds the page in the vertical plane in the line of vision with the 

 dorsal side of the figure uppermost and the cloacal end toward the observer, the relations 

 will become clearer. The right lateral wall of the right oviduct (ov in the light area) has 

 been cut away near the pomt of junction of the left oviduct {ov in center in dark area). 

 The figure shows a common tube leading into the cloaca. From this, it is seen that the 

 left oviducal opening is situated in the wall of the right aperture. 



Smith found the two openings in all his specimens, but, excepting in the youngest, 

 the right opening was predominant. This was markedly true in his two sexually mature 

 females as shown in Text-figures 14 and 15. In the cloaca in each figure the large shaded 

 area on the (fish's) right side is the opening of the right oviduct, the smaller shaded area 

 on the left the opening of the left tube. Note how very predominant the right opening 

 is in Text-figure 15. Here is Smith's statement on this condition in the fully mature 

 specimen referred to: '\ . . almost the entire urogenital sinus seems built around the very 

 large opening of the right uterus indicated by line-shading in the figure [No. 15 herein]. 

 In the hardened condition of the material, this opening is still large enough to admit 

 a thumb. The opening of the left uterus is much smaller". 



Here again is further proof of the unilaterality of functioning of the right oviduct of 

 the frilled shark. Shell gland, uterine enlargement, posterior opening into cloaca, each 

 overshadows its fellow on the left. 



