. Bulletin of the Natural History Museum Zoology. Fig. 71 Yoldiella curta. a, lateral external and internal view of left valve of the type specimen of Y. curta (USNM ) and b, the lateral external and internal view of the right valve of the type specimen of Y. miniscula (USNM No. 38415). Specimens from the Fish Commission Sta. 2084 North America Basin. (Scale = mm). mantle cavity. The outer and inner demibranchs are attached to the mantle and body respectively by tissue junctions. Depending on the size of the individual there are 11-16 alternating gill plates. The labial palps a
. Bulletin of the Natural History Museum Zoology. Fig. 71 Yoldiella curta. a, lateral external and internal view of left valve of the type specimen of Y. curta (USNM ) and b, the lateral external and internal view of the right valve of the type specimen of Y. miniscula (USNM No. 38415). Specimens from the Fish Commission Sta. 2084 North America Basin. (Scale = mm). mantle cavity. The outer and inner demibranchs are attached to the mantle and body respectively by tissue junctions. Depending on the size of the individual there are 11-16 alternating gill plates. The labial palps are moderately large, extending approximately 1/3 across the body and have between 13-19 wide ridges on their inner faces. The foot is large and well-developed. A large byssal gland is present, with little obvious internal structure as seen in whole mounts. At the point where the gland opens to the exterior the surrounding tissue contains acidophilic gland and basiphilic cells. As in other species of Yoldiella there is a broad band of posterior retractor muscles. The latero- posterior retractor muscle is inserted ventrally on lateral body wall. There are three major pairs of anterior pedal retractor muscles which, from the neck of the foot, pass to either side of the oesophagus and insert on the shell posterior to the anterior adductor muscle. Another smaller pair of anterior retractor muscles insert immediately posterior to the anterior adductor and pass within the ventral visceral margin at epithelia to the region of the mouth (Fig. 76b). Posterior to these a second pair of muscles pass vertically from the dorsal shell margin to the labial palps. The cerebral ganglia are relatively large, as are the elongate-oval pedal ganglia. The visceral ganglia are smaller, cylindrical and lie close to the antero-ventral margin of the posterior adductor muscle. The mouth is a short distance posterior to the anterior adductor muscle. The oesophagus curves dorsally and anteri- orly before tu
Size: 1346px × 1856px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bhlconsortium, bookc, bookcentury1900, bookcollectionbiodiversity
