. Bulletin of the Natural History Museum Zoology. . Fig. 45. Propeleda paucistriata. a, internal morphology as seen from the right side; b, part of the left side of the same specimen to show details of the course of the gut; c, the internal morphology as seen from the left side of a much larger specimen. All specimens taken from Atlantis II station 203 from the Angola Basin. For identification of the parts see text-figure 7, p. 106. Scales = 1mm. and extend from the posterior visceral mass to the anterior limit of the posterior adductor. There are at least 22 gill plates in larger specimens. A
. Bulletin of the Natural History Museum Zoology. . Fig. 45. Propeleda paucistriata. a, internal morphology as seen from the right side; b, part of the left side of the same specimen to show details of the course of the gut; c, the internal morphology as seen from the left side of a much larger specimen. All specimens taken from Atlantis II station 203 from the Angola Basin. For identification of the parts see text-figure 7, p. 106. Scales = 1mm. and extend from the posterior visceral mass to the anterior limit of the posterior adductor. There are at least 22 gill plates in larger specimens. A slender extension of the axis extends from each gill from ventral to the posterior adductor to the inner junction between inhalent and exhalent siphons. From the large combined stomach and style sac the course of the hind gut takes it first dorsal and posterior to the stomach and then to the left side of the body where it makes a small loop. From there it passes ventral to the umbo to the right side of the body where it makes a much larger loop at the perimeter of the viscera and passing close to the inner face of the anterior adductor. From there it passes mid-dorsally to the anus. The mouth is set some distance posterior to the anterior adductor muscle. The oesophagus is broad and elongate and the combined stomach and style sac is positioned vertically in the posterior part of the visceral mass. The pedal ganglion is large and lies immediately anterior to the junction of mid gut and hind gut. The shell surface in some larger specimens is covered with epifaunal solitary hydroids. This would indicate that P. paucistriata lives close to the surface of the sediment. This is also suggested by the fact that the posterior tips of the shells of larger specimens are broken. We believe that this is the result of predation on the siphons. The extreme post-adductor elongation of the shell is advanta- geous in that it provides distance between predator and the more vulnerable viscera wit
Size: 2516px × 993px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bh, bookcentury1900, bookcollectionbiodiversity, bookleafnumber62
