578 
ACTINOPTEETQII. 
Type. Hinder half of cranium ; British Museum. 
The type species, with skull about 0*1 in length and 0'05 in 
maximum width. Two upper preopercular spines inconspicuous. 
Form. ^ Log. Lower Eocene (London Clay) : Sheppey, Kent. 
P. 9432. Well-preserved postorbital portion of cranium, the type 
specimen figured by Konig. The two median frontal 
ridges are shown. Old Collection. 
35719. Eemains of head displaying the right preoperculum, which 
is shown, nat. size, in the accompanying fig. 21 a. The 
Pig. 21. 
Ampheristus toliapicu&\ right preoperciiluin, outer aspect (A), and hinder 
portion of cranium, upper aspect (B). nat. size, e'po., epiotic ; facettes ; 
/r., frontal; orh., orbit; pto., pterotic; s.occ., supraoccipital; x., squa¬ 
mosal (?); 1-4, ridges. 
lowermost spine is broken, and the upper end of the bone 
is incomplete. A ridge and facette (/) indicate the 
attachment of the bony suborbital stay. Purchased, 1860. 
P. 630. Fragmentary head and three anterior vertebrae, labelled by 
Agassiz and Egerton as intended to be the type specimen 
of Gonioynathus coryiphaenoides. Egerton Coll. 
35718. Imperfect head. Purchased, 1860. 
P. 9433-35. Three imperfect heads, one showing 8 pairs of 
branchiostegal rays. History unknown. 
38899. Eemains of head. Bowerhank Coll. 
P. 4143, P. 4540. Five imperfect specimens, the first showing the 
frontal ridges, as represented in the accompanying 
