450 Bashford Dean Memorial Volume 



ment to the contrary, one might assume that the two oviducts of Heptanchus are of 

 equal size; but if I interpret Daniel's fig. 251a correctly, the right oviduct is considerably 

 larger than the left. 



UROGENITAL SYSTEM OF THE MALE 

 I have no adult male specimens of Chlamydoselachus, and the literature on the male 

 reproductive organs is very fragmentary. No description of the mesonephroi in the 

 male has been found. It seems best to present the observations of each author in chrono' 

 logical order, reserving for special treatment the myxopterygia or "claspers.'" 



EXCRETORY AND INTERNAL GENITAL ORGANS 



Giinther's (1887) material consisted of tv/o males, the larger 1473 mm. long. Both 

 specimens seemed to be sexually mature. The testes are narrow elongate bodies of 

 nearly equal size, about 127 mm. long and 13 mm. broad at the broadest part. They 

 reach close to the anterior end of the abdominal cavity. In one of the males the arrange- 

 ment of the urogenital organs and ducts, as well as of the external openings, is perfectly 

 symmetrical (Figure 17, plate V), while in the other (Figures 18 and 19, plate V) the 

 left side shows a much more highly developed condition than the right. In the former 

 (bilaterally symmetrical) specimen, the urogenital organs are not further described. In 

 the latter specimen the left ductus deferens is much wider than the right, and its interior 

 contains low, circular, close-set septa (Figure 16, plate IV). Only faint traces of septa 

 can be seen in the right duct. They are limited to the lower three or four inches of the 

 duct. The left ductus deferens opens into ''the urinary bladder, if a bottle-shaped 

 dilatation which terminates externally in a single small conical papilla may be so called." 

 The right ductus deferens opens by a sHt at the side of the papilla directly into the cloaca. 



It is not clear how many male specimens Hawkes (1907) examined. In describing 

 the urogenital system of the male, she refers to "my specimen," but in her description of 

 the abdominal pores she unrites concerning "one of the males examined." She states 

 that in the male there are two urogenital apertures (Text-figure 90b, after Hawkes), 

 each being the outlet of an oval urogenital sinus (Bl.) which Giinther described as a urinary 

 bladder. Anteriorly, the sinus coimnunicates by a very small aperture with a second and 

 larger chamber (R.S.), which is continuous with the ductus deferens (V.D.) or meso- 

 nephric duct, and possibly functions as a seminal vesicle. The ductus deferens has 

 (presumably on its inner surface) one or more projecting spiral folds which run from one 

 end of the duct to the other. In the posterior 100 mm. of the length of the duct, the 

 folds are very obvious, but from this point forw^ard they become almost invisible to the 

 naked eye. In the posterior part of the duct the folds are very close together (Giinther 

 describes them as "circular" foldsj. Hawkes further states that the lumen of the left 

 ductus deferens (which Giinther found, in one of his specimens, to be better developed 

 than the right) is very irregular in diameter "in my specimen." At its widest, the duct 

 measures about 5 mm., but where narrowest it allows only the passage of a bristle. 



Since the excretory and the internal genital organs of the male Chlamydoselachus 

 are so imperfectly known, a comparison with other elasmobranchs would be unprofitable. 



