Dr. R. H. Tiaquair on Palceozoic Fishes. G7 



lar laterally ; frontal lobes 

 rounded. 



«*. Upper crests of anterior caudal 

 segments more elevated, sides 

 of segments straighter, mucli 

 less noticeably convex ; vesicle 

 narrower abruptus, Poc, $ . 



h^. Uppercrest of tail scarcely notice- 

 ably elevated ; sides of seg- 

 ments convexly rounded ; 

 vesicle wider Woochcardii, Poc, $ . 



The remaining species of this genus, described under 

 the name loctonusy are : — 



Urodacus manicaius, Thorell (Ann. & Mag. Xat. Hist. 1876, 

 xvii. p. 14 ; id. Act. Soc. Ital. Sci. Xat. xix. p. 261 &c.), 

 from Australia, which, according to Kraepelin, is iden- 

 tical with U. novce-hollanduBj Peters. 



Urodacus orthurus, Thorell (Act. Soc. Ital. Sci. Nat. xix. 

 p. 190), of which the locality is unknown. — Kraepelin 

 suggests that this species may be identical with Darwinii 

 or jylanimanus^ or both. I have no hesitation in saying 

 that with Darwinii it is certainly not identical, if any 

 value is to be placed upon its description, and that the 

 evidence as to its identity with ^j'^a/ima/zzfs is stronger on 

 the negative than on the positive side. 



IX. — Notes on Palceozoic Fishes. — No. II.* 

 By R. H. Traquair, M.D., LL.D., F.R.S. 



[Plate I.] 



Hitherto the remarkable plates known as Psammosteus have 

 been found only in strata of Upper and Middle Devonian age 

 in Scotland and in Russia. Through the kindness of 

 Dr. Woodward, F.R.S., Keeper, and Mr. A. Smith Wood- 

 ward, Assistant-Keeper, of the Geological Department in the 

 British ^Museum, I have now the privilege of describing and 

 figuring a new species from the Lower Old Red Sandstone 

 of the West of England. 



Psammosteus anglicus, sp. n. (PI. I. figs. 1, 2.) 



This plate is represented, natural size, in PI. I. fig. 1. It 

 is oblong-ovate in shape, 3f inches in length by 2^ in 



* For No. I. see Ann. & Mag. N. H. ser. 6, 1894, vol. xiv. pp. 368-374. 



