CEPHALASPID2E. 
177 
Postero-lateral cornua exceeding the shield in 
length. Either aspis (p. 193 j. 
II. Anterior dorsal body-scales fused into a con¬ 
tinuous plate. 
Cornua divergent ; shield larger than the 
dorsal plate . Auchenaspis (p. 195)^ 
Cornua rudimentary and bordering the dorsal 
plate, which is larger than the shield. . . . Didymaspis (p. 199). 
Genus CEPHALASPIS, Agassiz. 
[Poiss. Foss. vol. ii. pt. i. 1835, p. 135.] 
Syn. Eucepholaspis, E. R. Lankester, Fishes Old Red Sandst. pt. i. 
(Pal. Soc. 1870), p. 43. 
Hemicyclaspis, E. R. Lankester, ibid. p. 43. 
Zenaspis, E. R. Lankester, ibid. p. 43. 
• *, 
Postero-lateral angles of shield more or less produced into acute 
cornua, not exceeding the shield in length. Body elevated, and 
triangular in transverse section. Flank-scales in three series, the 
Fig. 18. 
w. c. r 
Cepkalaspis lyelli, Ag.—Outline sketch of shield, restored by Lankester. a. f, 
antorbital fossas ; a. p., antorbital prominences; i. g., interorbital ridge or 
gimove; i. p., interorbital prominence ; o. r., orbital rim ; ra. c., marginal 
cells ; p. o. v., postorbital valley ; p. a posterior angle ; p. c., posterior 
cornu ; p. r., posterior ridge ; p. s., posterior spine ; r., rim. 
upper series of each side meeting in the mesial line above, the middle 
series deepest, and the lowermost forming an infero-lateral fringe 
often serrated ; ventral scales apparently small, arranged in V-shaped 
x 
PAET II. 
