﻿PTERASPIDJ5. 



167 



Pteraspis crouchi, Laukester. 



1865. Pteraspis crouchii, E. R. Lankester (ex Salter, MS.), Rep. Brit. 



Assoc. 1864, Trans. Sect. p. 58. 

 1868. Pteraspis crouchii, E. R. Lankester, Fishes Old Red Sandst. pt. i. 



(Pal. Soc), p. 30, pL iii., pi. iv. fig. 5, pi. vi. figs. 4, 7, 8, pi. vii. 



figs. 4, 8, 11. 

 1887. Pteraspis crouchii, 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 Pi rostrata, and its ventral shield is 

 probably described as Scaphaspu recta. 



Form. Sf Loc. Lower Old Red Sandstone (Cornstones) : Whitbatch 

 and Ludlow, Herefordshire, and Abergavenny, Monmouthshire. 



33317 a, b. Two imperfect median discs ; Ludlow. 



Purchased, 1858. 



45954, 45956. Two imperfect discs, one with fragments of the 

 spine ; Downton Hall. Lightbody Bequest. 



P. 3246. Internal cast and fragments of disc ; near Ludlow. 



EnnisTcillen Coll. 



45941-42. Two portions of rostrum figured by Lankester, op. cit, 

 pi. iii. figs. 12, 13 ; Leyster's Pole. Lightbody Bequest. 



45967. Imperfect rostrum, dorsal aspect, figured ibid. pi. vi. fig. 7 ; 

 Short AVood, near Ludlow. Lightbody Bequest. 



45951, 45965. Eractured rostrum from Hayton's Bent, and a frag- 

 ment from Downton Hall. Lightbody 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 iu the 

 accompanying woodcut (fig. 16). Baugh Coll. 



The undermentioned ventral shields are probably referable to 



