PTERASPIDiE. 
167 
Pteraspis crouch!, Lankester. 
1865. Pteraspis crouckii, E. R. Lankester (ex Salter, MS.), Rep. Brit. 
Assoc. 1864, Trans. Sect. p. 58. 
1868. Pteraspis crouckii, E. R, Lankester, Fishes Old Red Sandst. pt. i. 
(Pal. Soc.), p. 30, pi. iii., pi. iv. fig. 5, pi. vi. figs. 4, 7, 8, pi. vii. 
figs. 4, 8, 11. 
1887. Pteraspis crouckii, A. S. Woodward, Proc. Zool. Soc. p. 478, 
wo ode. 
Type . Dorsal shields; British Museum, Ludlow and Oxford 
Museums. 
Rostrum slender and acutely pointed, upwardly curved, its maxi¬ 
mum width being about half as great as its length. Disk oblong, 
heart-shaped, abruptly tapering posteriorly; dorsal spine large; 
cornua large and broad, obtusely pointed. 
This is a smaller species than P. rostrata , and its ventral shield is 
probably described as Scaphaspis recta . 
Form. Sf Log. Lower Old Red Sandstone (Cornstones) : Whitbatch 
and Ludlow, Herefordshire, and Abergavenny, Monmouthshire, ptez**.<u>, 
33317 a, b. Two imperfect median discs; 
Ludlow. 
Purchased , 1858. 
45954, 45956. Two imperfect discs, one with fragments of the 
spine ; Downton Hall. Lighthody Bequest . 
P. 3246. Internal cast and fragments of disc ; near Ludlow. 
Enniskillen Coll . 
45941-42. T wo portions of rostrum figured by Lankester, op. cit . 
pi. iii. figs. 12, 13; Leyster’s Pole. Lighthody Bequest. 
45967. Imperfect rostrum, dorsal aspect, figured ibid, pl.vi. fig. 7 ; 
Short Wood, near Ludlow. Lighthody Bequest. 
45951, 45965. Fractured rostrum from Hayton’s Bent, and a frag¬ 
ment from Downton Hall. Lighthody Bequest. 
42163. Imperfect disc, doubtfully of this species; Herefordshire. 
The specimen shows the sensory canals injected with 
mineral matter, and is described and figured by the pre¬ 
sent writer, loc . cit., the figure being reproduced in the 
accompanying woodcut (fig. 16). Baugh Coll . 
&/So o', A-c • p ' 
The undermentioned ventral shields are probably referable to 
