﻿CEPHALASPIDJE. 1 89 



the encircling scutes being relatively smaller and more numerous. 

 In some Forfarshire specimens, moreover, the superficial ornamen- 

 tation is in the form of distinct tubercles. 



The new specimens obviously confirm Lankester's suspicion, that 

 there is no " nuchal " plate behind the anterior shield, as was con- 

 sidered possible by Egerton. 



Numerous sections of the trunk in various directions show no 

 traces of a hard internal skeleton, and thus are also confirmatory of 

 previous conclusions on the subject, based upon the study of exam- 

 ples of the typical species. 



The only fin preserved in Mr. Piper's fossils is the dorsal, which 

 seems to be incompletely shown in No. P. 6023. There are no well- 

 defined fin-rays, the supporting structures being small, oblong, cal- 

 cified plates, closely fitted together, and placed end to end in vertical 

 parallel series. The arrangement is very suggestive of that of the 

 fragmentary fossils described by Lankester from the Bush Pitch Beds 

 under the name of KallostraTcon podura (see p. 175). 



45944. Type specimen of Cephalaspis ornata, Egerton ; Tilestones, 

 Ludlow. Lightbody Bequest. 



P. 673, P. 676. Two portions of shields ; Auchenaspi s-Grits (Pas- 

 sage Beds), Ledbury, Herefordshire. Egerton Coll. 



P. 3238-39. Four similar specimens, one being in counterpart; 

 Auchenaspis-Grits, Ledbury. Ennishillen Coll. 



P. 6023. Block of sandstone with more or less fragmentary remains 

 of about twelve individuals, shown, of the natural size, in 

 PI. X. fig. 1 ; red sandstone in Passage Beds, Ledbury. 



Presented by George H. Piper, Esq., 1889. 



P. 5317. Crushed portions of the shield and scaly trunk of two 

 associated individuals, one displaying the operculum ; 

 red sandstone, Ledbury. 



Presented by George H. Piper, Esq., 1887. 



P. 6260. Imperfect shield and anterior portion of the caudal region, 

 the latter fractured and showing the ventral scales (PI. X. 

 fig. 4, v.) ; red sandstone, Ledbury. 



Presented by George H. Piper, Esq., 1890. 



P. 6261. Imperfect shield and anterior portion of the caudal region, 

 showing well-preserved dorsal ridge-scales ; red sandstone, 

 Ledbury. Presented by George H. Piper, Esq., 1890. 



P. 6108. Portion of the anterior shield broken in such a manner as 

 to expose the irregular polygonal dermal calcifications 



