. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. SURVEY OF STRUCTURE 45 Reference to Text-fig. 25 will show the small volume of the lumen compared with the total volume of the sac. Between the inner epithelium and the tunica externa is a voluminous layer of lamellar fibres belonging to the submucosa, which thus makes up most of the total volume. Clearly this is a regressed swimbladder, which is doubtless relatively better developed during the early life-history. In having a swimbladder with clearly separate glandular and resorbent parts, Stylo
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. SURVEY OF STRUCTURE 45 Reference to Text-fig. 25 will show the small volume of the lumen compared with the total volume of the sac. Between the inner epithelium and the tunica externa is a voluminous layer of lamellar fibres belonging to the submucosa, which thus makes up most of the total volume. Clearly this is a regressed swimbladder, which is doubtless relatively better developed during the early life-history. In having a swimbladder with clearly separate glandular and resorbent parts, Stylophorus is evidently an euphysoclist. But it is unusual in having these two parts reversed in position, for in most euphysoclists (without an oval) the fore part is secretory, while the rear part is Text-fig. 26. Swimbladder of Stephanoberyx monae, seen (a) from above. In (b) is shown the blood supply to the right lobe of the gas-gland, cl, capillary hop; gg, gas-gland; ov, oval; rm, rete mirabile. (a, x 5-5; b, x 17.) Order BERYCOMORPHI Family Stephanoberycidae Stephanoberyx monae Gill (Text-fig. 26) Oregon St. 1426 (290 07' N., 870 54' W.), 24. ix. 57, 600 fathoms, trawl. Standard length 83-5 mm. (16-0 x 8-o mm.). The swimbladder of this species is ellipsoidal in form and extends down most of the length of the upper part of the body-cavity. The blood supply for the retia enters the floor of the sac close to its posterior end. The artery and vein form two long retia mirabilia (about 8 mm. in length). In the fish dissected the retia were dis- placed in position, but presumably extend forward along the swimbladder floor. Each rete runs to a corresponding lobe of the gas-gland, where the capillaries form loops running through the secretory tissue. The retia are thus unipolar in structure. Immediately above this point of entry of the retial blood supply there is an oval on the roof of the sac. This measured about 5 mm. in diameter and was partly closed. The capillary ne
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