. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. 380 Bashford Dean Memorial Volume THE ANAL FIN In the endoskeleton of the anal fin of Chlamydoselachus (Text'figures 48 and 52 after Garman and Deinega respectively) there is some fusion of proximal elements, and even a slight amount of fusion of distal elements. The elements of the basal series are usually oriented in a different direction from the distal elements. In the adult, this fin skeleton is very long and slender (in an anteroposterior direction). The same is true of the anal fin skeleton of a 225'mm. embryo figure
. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. 380 Bashford Dean Memorial Volume THE ANAL FIN In the endoskeleton of the anal fin of Chlamydoselachus (Text'figures 48 and 52 after Garman and Deinega respectively) there is some fusion of proximal elements, and even a slight amount of fusion of distal elements. The elements of the basal series are usually oriented in a different direction from the distal elements. In the adult, this fin skeleton is very long and slender (in an anteroposterior direction). The same is true of the anal fin skeleton of a 225'mm. embryo figured by Osburn, 1907 (Fig. 6, pi. IV). In this embryonic specimen the fusion of basal elements is not so pronounced. The separa- tion of the fin skeleton from the vertebral column is very marked. In Heptanchus cinereus (Daniel, 1934, Fig. 57 after Mivart) there is a fairly large basal element in series with some smaller basal elements, all apparently formed by the fusion of Text'figure 52. Endoskeleton of the anal fin of Chlamydoselachus anguineus (showing basals 1-20). After Deinega, 1909, Fig. 13, pi. IV. THE CAUDAL FIN The general appearance of the cartilaginous supports for the dorsal and ventral lobes of the greater part of the tail fin is shown in Deinega's (1909 and 1923) Fig. 9, pi. Ill, which is too large for satisfactory reproduction here; also in Carman's () PI. 14, which was drawn from a specimen in which the tip of the tail had been mutilated during life. Details are better shown in Goodey's () drawings reproduced herein as Text-figures 31 and 36. The cartilaginous supports for the ventral lobe of the caudal fin of Chlamydosela' chus are suppHed almost entirely by the haemal spines, which belong to the axial skeleton. The occurrence of small radials distinct from the haemal spines is confined to the anterior portion (Text-figures 31 and 48) of the ventral lobe, and these radials are possibly seg- mented off from the haemal spines. The cartilagino
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