454 Bashford Dean Memorial Volume 



The abdominal pores of my female specimens of Chlamydoselachus are a pair of 

 short canals leading from the ventral portion of the body cavity, by the most direct 

 route, to their external openings on each side of the ventral surface of the body just 

 posterior to the cloaca. The body cavity extends along each side of the cloaca, but not 

 so far caudad in its ventral as in its dorsal portion. The difference (about 15 mm.) is 

 approximately equal to the length of the abdominal pores. The distal or superficial half 

 of each canal lies just beneath the integument which is usually upraised to form a low 

 ridge. The inner opening is somewhat funnel'shaped and is large enough to admit a pencil. 

 The canals, when probed from the body cavity, are found to be quite uniform in caliber, 

 well-rounded and about 5 mm. in diameter. The external openings (ah. p. in Text'figures 

 85 to 88) vary considerably in si2;e. When well developed, as in specimens IV and III 

 (Text-figures 85 and 86) they are elliptical, about 8 mm. long, and face obliquely ventrad, 

 laterad and caudad. In specimens I and II (Text-figures 87 and 88) they are usually 



Text-figure 98. 



Pelvic fins, abdominal pores and 



cloaca! aperture of a 1220-mm. 



female Chlamydoselachus. 



After Garman, 1885.2. PI. I. 



round and comparatively small, but one is absent. On the right side of No. II the external 

 opening is so small that it barely admits a probe. In the single case (specimen No. I) 

 where an external opening is absent, the canal is fully developed internally but is closed 

 externally by the integument. 



The external openings of the abdominal pores in Carman's (1885.2) specimen, a large 

 female, are shown in his plates, reproduced as my Text-figures 98 and 89. Garman states 

 that the mouth of each abdominal pore is inflated into a broad flap, by which the pores 

 are hidden. Hawkes (1907), in a figure reproduced as my Text-figure 90a, shows the 

 cloacal region of a female with two closed abdominal pores. 



The specimens thus far considered are all females. It remains to describe the condi- 

 tion of the abdominal pores in the male. Giinther's (1887) illustrations include two 

 figures (my Figures 17 and 18, plate V) showing the abdominal pores of his male speci- 

 mens. One is normal, showing two open pores similar to those of the typical female; 

 the other is anomalous, possessing only a single abdominal pore, which is unusually large. 

 In his text, Giinther states that this single abdominal pore is situated immediately behind 

 the cloaca and "in the median line (or very slightly to the left of it)" but his figure shows 

 it definitely on the left side. Hawkes (1907) writes: "One of the males examined has 

 two abdominal pores of which the right is the better developed." In the explanation of 

 her diagrammatic text-figure (my Text-figure 90b) the left pore is said to be closed. 



From the meager evidence at hand it does not appear that there is any important 

 difference between the abdominal pores of the male and the female, but it is clear that 



