126 



WEALDEN AND PURBECK FOSSIL FISHES. 



Remarks. — This geilus occurs chiefly in the Lithographic Stone of Bavaria. 

 France, and Northern Spain (A. vidali, II. E. Sauvage, Mem. R. Acad. Cienc. 

 Barcelona [3], vol. iv, no. ;> > : >, 1903, p. 13, pi. ii, fig. 2). One species has been 

 identified from the Wealden of Belgium (A. robustus, R. H. Traquair, Poiss. Weald. 

 Bernissart, Mem. Mus. Roy. Hist. Nat. Belg., vol. v. 1911, p. •"><>, pi. xi), and the 

 same or ;i closely allied form is recorded from the Lower Cretaceous of Castella- 

 mare, Naples (F. Bassani and G. D'Erasmo, Mem. Soc. Ital. Sei. XL [3], vol. xvii, 

 1912, p. 234, pi. iii, fig. 3, pi. vi, figs. 1, 2, text-figs. 13—15; also (J. D'Erasmo, 

 Palseont. Italica, vol. xxi, 1915, p. 15, pi. i. fig-. 8, text-fig. 22). Dr. Traquair's 



Fi... 38. Mthalion robustus, Traquair ; restoration of skeleton, scales omitted, reduced in size.- Wealden; 

 Bernissart, Belgium. After R. II. Traquair. br., branchiostegal rays; (/..clavicle: mn., mandible; 

 mx., maxilla ; o., orbit ; op., operculum; pop., preoperculum ; s.o., cbeek-plates ; s.op., suboperculum. 



sketch of the restored skeleton of the Wealden A. robustus is reproduced in Text- 

 fig. 38. 



1. iEthalion valdensis, A. S. Woodward. Text-figure :'»'.» 



L907. Leptolepis valdensis, A. S. Woodward, Ano. Mag. Nat. Hist. [7 |, vol. xx. p. 93, pi. i. 



Type.— Imperfect fish ; British Museum. 



Specific Characters.— A stout spec.es attaining a length of about 40 cm. 

 Length of head with opercular apparatus exceeding the maximum depth of the 

 trunk, which equals aboul one-third the length from the pectoral arch to the base 

 ol the caudal fin, and would probablv equal aboul one-fifth of the total Length of 

 the fish. Vertebras 60. Pelvic fins arising midway between the pectoral and anal 

 tins, opposite the front half of the dorsal, which arises much nearer to the occiput 

 than to the caudal fin and comprises 18 to 20 rays; anal fin with about L 4 rays, 

 arising slightly nearer to the caudal than to the pelvic pair. Scales rather large 

 and very deeply overlapping, some feebly crimped. 



Descri l Aion •'' Specimen:— The type specimen (Text-fig. 39) is still unique, 



