PLATE IY. 
Fig. Page 
1. Eugnathus orthostomus , Agassiz; head, pectoral fin, and 
scales, left lateral aspect.—Lower Lias ; Lyme Regis. 
cicj. Angular. hr. Branchiostegal rays. c.o. Circum- 
orbitals. d. Dentary. fr. Frontais. i.op. Interopercu- 
lnm. mx. Maxilla. op. Operculum, p.cl. Postcla- 
vicular scales, p.op. Preoperculum, p.t. Post-temporal. 
pa. Parietal, s.cl. Supraclavicle. s.mx. Supramaxilla. 
s.o. Suborbitals (postorbitals). s.op. Suboperculum. 
s.t. Supratemporal. sq. Squamosal. [P. 3633 b.J 293 
2. Eugnathus tenuidens , Agassiz, MS. ; left maxilla, outer 
aspect.—Lower Lias; Street. [P. 510.] 303 
3. Eugnathus minor , Agassiz ; left mandibular ramus, outer 
aspect.—Lower Lias ; Lyme Ptegis. [P. 3634 e.] 297 
