100 
ACTIXOPTEEYGII. 
antero-superior process. Scales large and smooth, those of the 
anterior portion of the flank with few large denticulations at least 
in their lower half; dorsal ridge-scales with slender acumination, 
Pigs. 19-21. 
20 a 
Fig. 19 .'—Lepidotus macrocheirus ; anterior half [of right mandibular ramus 
from the outer and oral (a) aspects.—Oxford Clay; Peterborough. [No. P. 
6839.]— d., dentary; spl., splenial. 
Fig. 20 .—Lepidotus leedsi\ left operculum (op.) and suboperculum (s.op.), outer 
aspect.—Oxford Clay; Peterborough. [No. P. 6837.] 
Fig. 20a.—Ditto; imperfect right mandibular ramus, outer aspect, of same 
specimen, showing angular (ag.) and dentary (d.). 
Fig. 21.—Ditto ; left dentary, outer aspect, and lateral view of tooth (a ).— 
Kimmeridge Clay ; Weymouth. [No. 41964 c.] 
All these figures two-thirds nat. size. 
In this species the operculum is much larger in proportion to the 
mandible than in L. macrocheirus. 
Form. 6f Loc. Oxfordian: Huntingdonshire. Kimmeridgian: 
Dorsetshire. 
P. 6837. Type specimen, comprising the associated imperfect right 
mandibular ramus, squamosals, other cranial bones, epi- 
hyal, ceratohyals, left operculum and interoperculum, 
