. Bulletin - United States National Museum. Science. 184 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. (fig. 49, p. 72) and the Cyclosalpas (pi. 1, fig. 1; pi. 3, fig. 9; pi. 7, fig. 19; pi. 11, fig. 26), we might assign eight or perhaps nine to the body muscle series, preferably nine. In any case the two species closely agree in musculature, body muscle IX (or the basal cloacal muscle, if one prefers so to name it) being the same in the two, showing the same abortive anterior branch below and the same well developed posterior branch passing around the body between the cloacal siphon and the gu
. Bulletin - United States National Museum. Science. 184 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. (fig. 49, p. 72) and the Cyclosalpas (pi. 1, fig. 1; pi. 3, fig. 9; pi. 7, fig. 19; pi. 11, fig. 26), we might assign eight or perhaps nine to the body muscle series, preferably nine. In any case the two species closely agree in musculature, body muscle IX (or the basal cloacal muscle, if one prefers so to name it) being the same in the two, showing the same abortive anterior branch below and the same well developed posterior branch passing around the body between the cloacal siphon and the gut evagination. The intermediate muscle is large and the horizontal muscle well developed. <There are five oral sphincters in each lip. The first and. Fig. 141.—Apsteinia asymmetrica, embryo. A dorsolateral view of the atrial siphon and the ADJACENT PARTS. X 102 DIAMETERS. second sphincters of the lower lip lie upon the incurved portion of the lip. Posteriorly they unite to form the dorsal oral retractor muscle, which is continuous with them alone. As in Apsteinia punctata (figs. 49, p. 72; and 50), the posterior end of the dorsal oral retractor abuts upon the front edge of the first body muscle. Also the ventral oral retractor divides posteriorly into dorsal and ventral branches, the dorsal one of which runs back as far as the eighth body muscle, the ventral branch being shorter. In A. asym- metrica it reaches to the middle of the fifth body muscle, being a little longer than in A. punctata. The ventral oral retractor muscle divides anteriorly to form muscle 5 of the lower lip and muscle 4. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States National Museum; Smithsonian Institution; United States. Dept. of the Interior. Washington : Smithsonian Institution Press, [etc. ]; for sale by the S
Size: 1699px × 1471px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
