. Bulletin of the British Museum (Natural History). OSTEOLOGY OF THE D ENT I CI PI T I n A E 253. 1 mm. PSr Fig. 29. Caudal fin skeleton. Intermuscular bones removed for clarity. Left lateral view. P1-3 : first to third preural vertebrae. (short, but segmented distally) and a series of procurrent " spines ", five dorsally and three ventrally (Text-figs. 29). These " spines " have a deeply divided base, but cannot be separated into left and right halves. Each dorsal procurrent " spine " is articulated with a single vertebral element (the first with the neural spine
. Bulletin of the British Museum (Natural History). OSTEOLOGY OF THE D ENT I CI PI T I n A E 253. 1 mm. PSr Fig. 29. Caudal fin skeleton. Intermuscular bones removed for clarity. Left lateral view. P1-3 : first to third preural vertebrae. (short, but segmented distally) and a series of procurrent " spines ", five dorsally and three ventrally (Text-figs. 29). These " spines " have a deeply divided base, but cannot be separated into left and right halves. Each dorsal procurrent " spine " is articulated with a single vertebral element (the first with the neural spine of PU4 the second with PU3, the third with PU2, and the remaining two with the two epurals). The three ventral spines, however, all articulate with the expanded haemal spine of the third preural vertebra. Both dorsally and ventrally, the procurrent " spines " increase in length towards the fin, thereby forming a graded series with the segmented procurrent ray preceding the first and last (unbranched) principal caudal rays. These three procurrent rays are segmented distally, but the proximal portion resembles that of a " spine ". Thus, it seems certain that the spines are merely modified procurrent rays. The first preural centrum (PUi) is slightly longer than the second (Fig. 29). Its neural arch is complete but very narrow-based and short, the neural spine showing a correspondingly great reduction in length to little more than a slight spur. The. 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 British Museum (Natural History). London : BM(NH)
Size: 1823px × 1371px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., 1968, boo, bookauthorbritishmuseumnaturalhistory, bookcentury1900
