44 



DISCOVERY REPORTS 



Family Rondeletiidae 

 Rondeletia bicolor Goode & Bean 

 Parr (1929) records the absence of the swimbladder in this species. 



Order GIGANTUROIDEA 



Regan (1925) included the absence of a swimbladder in his diagnosis of this order. I was unable to 

 find any trace of this organ in a Gigantura vorax of standard length 74 mm. 



Order LYOMERI 



Bertin (1934) has given an account of the internal organs of Eurypharynx pelecanoides and Sacco- 

 pharynx ampullaceus, but no mention is made of a swimbladder. I was unable to find this organ in 

 an individual of the first species. 



Text-fig. 25. Swimbladder of Stylophorus chordatus, seen (a) from below, and (b) in the body-cavity of the fish, en, capillary 

 network; gg, gas-gland; k, kidney; lu, lumen of swimbladder; rm, rete mirabile; sb, swimbladder; st, stomach, (a, x 15; 

 b, x 1-8.) 



Order ALLOTRIOGNATHI 



Family Stylophoridae 

 Stylophorus chordatus Shaw (Text-fig. 25) 

 St. 296, 8° 12' N., 18 49' W., 26. viii. 27, TYF, 45o-5oo(-o) m. Standard length 177 mm. 



This individual contained a small elongated swimbladder, lying just below the black-speckled 

 kidneys and originating a little before the pyloric end of the stomach. The sac measured about 

 12-5 mm. in length and i-o mm. in diameter and is attached by a mesentery to the dorsal wall of the 

 stomach. 



Within the mesentery is an artery and vein running close together to the anterior end of the sac. 

 The two vessels continue together for about 3 mm. along the left-hand lateral walls and then sub- 

 divide to form a single rete mirabile having a length of about 2 mm. The rete enters the lumen of the 

 sac about half-way along its length (of about 4 mm.). 



Examination of serial transverse sections revealed the disposition of the resorbent and glandular 

 parts of the swimbladder. The capillaries of the former lie just below the inner epitheleum and occur 

 over much of the lumen anterior to the point of entry of the rete. The glandular tissue lies behind this 

 point in the posterior half of the lumen. In supplying the gland, the retial capillaries do not unite 

 to form larger vessels. The rete is thus unipolar. 



