18 



WEALDEN AND PURBECK FOSSIL FISHES. 



exhibits well its characters. The anterior tubercles in the basal half are the 

 largest, those near the posterior border being relatively small and few. The fused 



ridges are in part slightly beaded. Some of the posterior 

 denticles, preserved in the apical half, are rather large. 

 The sharply arched form of the spine is especially note- 

 worthy. 



Horizon and Localit//. — Middle Purbeck Beds : Swanag^e, 

 Dorset. 



Si 



3. Asteracanthus granulosus, Egerton. 



Text-fig. 9. 



1854. Jsferacanthus granulosus, P. M. G. Egertou, Ann. Mag. Nat. Hist. 

 [2], vol. xiii, p. 433. 



1855. Asteracanthus granulosus, P. ]\I. G. Egerton, Figs, and DescriiJts. 

 Brit. Organic Eemains (Mem. Geol. Snrv.), dec. viii, pi. i. 



1859. Asteracanthus granulosus, Pictet and Campiclie, Foss. Terr. 

 Cretace St. Croix, p. 98, pi. xii, fig. 11. 



Tijpe. — Dorsal fin-spine ; British Museum. 



Specific Characters. — Dorsal fin-spine nearly similar in 

 form and proportions to that of ^4. verrucosus, but with 

 the ornamental tubercles relatively smaller and less closely 

 arranged. 



Description of Specimens. — The type spine, although 

 uncrushed, is a little abraded, incomplete at the apex, 

 and without the posterior denticles. The front border is 

 clearly shown to ho rounded, and the posterior face is also 

 only rounded, not keeled. The basal fragment of a second 

 specimen descril)ed and figured by Egerton proves that 

 the species sometimes attained a larger size than A. verrn- 

 cosifs. Another fine specimen, 30'5 cm. in length, found 

 ])y Mr. Philip Rufford in the Wadhurst Clay at Eccles- 

 bourne, near Hastings (Text-fig. 0), displays the side view 

 a little fractured by crushing. The sparse ornamental 

 P,„ o . , „ , tubercles tend to be arranged not only in longitudinal, 



r IG. 9. — Asteraccnitlnis granulo- " j o ' 



sws Egerton ; dorsal fin-spine, ]^^^^ j^jgQ sometimcs in trausverse series ; while near the 



ncrht side view, slisjntly more 



than one-half nat. size.— Weal- pointed taperinff apex they are fused as usual into lono^i- 



den (Wadhmst Clay): Eccles- ^ I b f J ^ & 



>)owme, near Hastings, Sussex, tudinal rido'es. The posterior denticles are seen to be 



Rufford Collection (B. M. no. '^ ^ 



P- 8939). relatively small. 



Horizon and Localities. — Wealden : Tilgate Forest, and Ecclesbourne, near 

 Hastings, Sussex. Also in the Lower Neocomian of St. Croix, Switzerland. 



i?rf 



w 



