﻿168 HETEROSTRACI. 



Pteraspis crouch i. They are described under the name of Scapliaspis 

 rectus, Lankester 1 , and are relatively longer and narrower than the 

 shields named S. lloydi, with more nearly parallel sides. 



Pteraspis crouch), Lank. — Portion of shield, dorsal aspect, showing sensory- 

 canals. [No. 42163.] From Proc. Zool. Soc. 1887. 



37389. Imperfect specimen associated with a fragment of the shield 

 of Phlyctcmaspis ; Heigh tiugton. Purchased, 1863. 



42149-50. Pour imperfect specimens ; Heightington. Baugh Coll. 



38034 a. Internal cast of shield, figured by Lankester, op. cit. pi. ii. 

 fig. 7 ; Worcestershire. Purchased, 1864. 



P. 4107-8. Two specimens ; Asylum Quarry, Abergavenny. 



Presented by Dr. D. M. McCullough, 1883. 



P. 4109. Internal cast of small shield ; from boulder in railway- 

 cutting, jVIaincliff, Abergavenny. 



-Presented by Dr. D. M. McCullough, 1883. 



The following species of Pteraspis have also been described, but 

 there are no examples in the Collection : — 



Pteraspis angustata, A. von Alth, Abhandl. k. k. geol. Eeichsanst. 

 vol. vii. pt. i. (1874), p. 45, pi. i. fig. 11, pi. iii. figs. 6, 7. — 

 Lower Devonian ; Iwanie and Kriszczatek, Galicia. [Im- 

 perfect shields.] 



Pteraspis mitchelli, J. Powrie, Geologist, vol. vii. (1864), p. 172 ; 

 E. E. Lankester, Fishes Old Eed Sandst. pt. i. (Pal. Soc. 



1 Fishes Old Eed Sandst. pt. i. (Pal. Soc. 1868), p. 23, pi. ii. figs. 5-8, 12, 

 13, pi. vii. fig. 2. 



