2 Dr. A. S. Woodward on some 



apices of the dorsal and anal fins, are generally wanting. 

 The fishes belong only to two genera and species, the one 

 Platysomid, the other Coelacanth. 



I. Ecrinesomus dixoni, gen. et sp. n. (PI. I. figs. 1-4.) 



The Platysomid fish, which attained a length of not less 

 than 25 cm., appears to be very common, and the series of 

 specimens obtained by Mr. Dixon exhibits nearly all its 

 principal characters. It is very deeply fusiform, with rounded, 

 not angulated, dorsal and ventral borders; the tail forming 

 at least half the total length of the fish and tapering rapidly 

 to a very slender pedicle for the caudal fin. The maximum 

 depth of the trunk is about equal to its length from the 

 pectoral arch to the base of the caudal fin. All the external 

 bones and scales, with the larger rays of the median fins, are 

 ornamented with closely-arranged parallel strife or very fine 

 ridges, which are generally disposed in a nearly vertical 

 direction. 



The head is always crushed in the fossils, and the parts 

 have so much decayed that they can only be studied in 

 impression. It is therefore difficult to distinguish the several 

 bones. The most conspicuous element is a nearly square 

 post-temporal plate (PI. I. figs. 1, 2, ptt.) r on which the 

 vertical striation tends to become subdivided into tubercles 

 near the upper and median border. A similar subdivision of 

 the ornament also occurs near the median ridge of the frontal 

 region. The cheek is completely covered with thin plates, 

 on which the ornamental stria? sometimes tend to become 

 concentric instead of vertical. The posterior circumorbitals 

 (fig. 2, po.) seem to have been divided into more numerous 

 plates than in known Platysomids ; but this may be a false 

 appearance due to infilled radiating brandies of the traversing 

 sensory canal. The maxilla is evidently a deepened plate, 

 but its precise shape is uncertain. The teeth are never seen, 

 and must have been minute. The operculum (fig. 2, op.) is 

 at least twice as deep as wide, and completely covered with 

 the neaily vertical wavy strise, which do not conform to its 

 border. The suboperculum (sip.) is relatively small and 

 similarly ornamented. 



The endoskeleton of the trunk is imperfectly ossified, the 

 cartilaginous vertebral arches and fin-supports being only 

 superficially hardened and thus appearing hollow in the fossils. 

 There are no traces of vertebral centra, and the arches are 

 only rarely seen. A close series of neurals is exposed in the 

 anterior part of the abdominal region in the type-specimen 



