﻿16*0 HETEROSTRACI. 



45950 a. More imperfectly preserved shield, apparently from the 

 same horizon and locality. Lighibody Bequest. 



45955. Internal cast and fragments of small shield ; Downton Hall, 

 near Ludlow. Lightbocly Bequest. 



P. 3245. Internal cast and fragments of small shield ; Leominster. 



Ennislcillen Coll. 



42153. Crushed and broken specimen ; locality unknown. 



Baugh Coll. 



46876. Internal cast of very broad, flattened specimen, doubtfully 

 of this species ; Cradley. Purchased, 1875. 



P. 193. Anterior two-thirds of similar specimen; Heigh tington. 



Weaver-Jones Coll. 



42159-60. Three very small shields, doubtfully of this species ; near 

 Trimpley, Worcestershire. Baugh Coll. 



38034. Two similar, but somewhat larger, shields, associated, and 

 showing portions of the external surface ; Trimpley. 



Purchased, 1864. 



An imperfectly known species, of large size, apparently closely 

 related to Pteraspis rostrata, has been obtained from the uppermost 

 Silurian and Lower Devonian of Galicia, and described under the 

 name of Pteraspis major, A. von Alth, Abhandl. k. k. geol. Beichs- 

 anstalt, Wien, vol. vii. pt. i. (1874), p. 44, pi. i. figs. 1-4, pi. iii. 

 figs. 3-5 \ The following specimen may be referable to this 

 form : — 



P. 6099. Portions of dorsal and ventral shields in natural apposition, 



the dorsal showing the posterior spine ; Upper Ludlow, 



Bilcze-on-Sered, Galicia. From the Alth Collection. — 



Presented by Prof. W. Szajnocha, 1888. 



It is interesting to note that the supposed ventral shield of P. 

 rostrata has already been recorded by v. Alth from the Upper Silu- 

 rian of Galicia (sttpra, p. 164, footnote). 



1 If the undetermined specimen described and figured in Alth's memoir (p. 71, 

 pi. v. fig. 33) pertain to this species, as suggested, the broad, rounded character 

 of the rostra region suffices to distinguish it from P. ro:<truta. 



