. The Cambridge natural history. Zoology. 48o FISHES arborescent appearance in transverse sections. Vertebral column acentrous. Genera:—Holoiotycliius^ (Fig. 277), Old Bed Sand- stone of Scotland; Devonian of Belgium, Eussia, North America, and East Greenland. Glyptohpis has a similar range. Fam. 4. Coelacanthidae.^—Scales cycloid. Paired fins ob- tusely lobate. Tail symmetrical but apparently gephyrocercal, usually with a protruding axial vestige of the disappearing terminal part of the tail and of the proper caudal fin. Eadialia of the functional caudal lobes agree in number with the con- ti
. The Cambridge natural history. Zoology. 48o FISHES arborescent appearance in transverse sections. Vertebral column acentrous. Genera:—Holoiotycliius^ (Fig. 277), Old Bed Sand- stone of Scotland; Devonian of Belgium, Eussia, North America, and East Greenland. Glyptohpis has a similar range. Fam. 4. Coelacanthidae.^—Scales cycloid. Paired fins ob- tusely lobate. Tail symmetrical but apparently gephyrocercal, usually with a protruding axial vestige of the disappearing terminal part of the tail and of the proper caudal fin. Eadialia of the functional caudal lobes agree in number with the con- tiguous neural and haemal arches and dermal fin-rays, the diagnostic feature of Smith Woodward's Actinistia. Proximal. Pia. 278.—Eestoration of Undina. gulo. Lower Lias of Dorset. Scales and supra- clavicle omitted. The ossiiied air-bladder is shown beneath the anterior part of the vertebral column. The facial bones in front of the orbit are unknown, and the cheek-plates are supposed to be arranged as in other Coelacanths. x about \. {From Smith Woodward.) radials of the dorsal and anal fins fused into a single, internally- forked basipterygium in each fin. Teeth simple. Vertebral column acentrous. The skull presents several interesting features. The hyomandibular and the palato-quadrate bar, for example, are fused on each side into a continuous tri- angular bone, articulating with the cranium above and with the lower jaw below. The opercular skeleton is reduced to an operculum and two jugular plates. A very singular feature in these Fishes is the ossification of the walls of the air-bladder (Fig. 278), a structural modification which has no parallel in Fishes, except in certain Teleosts (Siluridae and Cyprinidae)^ ' Traquair, Proc. Roy. Soc. Edinh. xvii. p. 388. - Reiss, Die Coelacanthinen, Palaeontogr. xxxi. 1888, p. 1 ; Smith Woodward, Brit. Mus. Cat. Foss. Fishes, ii. 1891, p. 394. ' See also Kurtus indicus, p. Please note that these images are extracted from scan
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
