128 
ACTTNOPTERTGII. 
and the anal, also remains of the pectoral and pelvic arches 
as shown loc. cif. 1894, pi. xliii. fig. 6 ; Barham. 
Presented hy the Hon. Robert Marsham., 1877. 
36097. Scattered remains of small specimen, including vertebrae 
and characteristic hinder scales of lateral line ; Lower 
Chalk, Dorking, Surrey. Purchased, 1861. 
Family CLUPEID^. 
Supraoccipital bone separating the small parietals in the median 
line : squamosal reduced, separated from parietals, and fused with 
pterotic; a basicranial canal; snout not produced ; cheek-plates 
reduced. Premaxilla small and maxilla relatively large and loose, 
both these bones entering the upper border of the mouth; usually 
two supramaxillaries; teeth acuminate, but usually feeble, some¬ 
times absent. Opercular apparatus complete, but few branchiostegal 
rays and no gular plate. Vertebral centra well ossified, some with 
very short transverse processes ; ribs nearly or completely encircling 
the abdominal cavity; haemal arches not much fused at the base 
of the tail. Intermuscular bones numerous. Fin-fulcra absent. 
Post-temporal bones in contact with postero-lateral angles of 
cranium ; post-clavicular plate overlapping the clavicle. Dorsal fin 
small, nearly median, Avithout adipose dorsal; anal fin variable in 
extent. Scales thin and deeply imbricating. In recent forms :— 
pseudo bran chi 80 present; a large air-bladder ; pyloric appendages 
numerous; oviducts complete. 
Synopsis of Genera represented hy Extinct Species. 
I. Ventral ridge-scales absent. 
A. Scales pectinated. 
Paired fins small, the pehdc pair 
opposed to the dorsal. 
B. Scales smooth and CAmloid. 
Maxilla rather short and arched, with 
small teeth ; paired fins large , , 
Maxilla A^ery long and slender ; teeth 
rudimentary or absent; paired fins 
small. 
Mouth small; fins small. 
II. Ventral ridge-scales present. 
A few finlets behind the anal fin; no 
dorsal ridge-scales . 
No fir lets ; dorsal ridge-scales between 
occiput and dorsal fin. 
No finlets; no dorsal ridge-scales.... 
Pseudoheryx (p. 129). 
Histiothrissa (p. 131). 
EnyrnuUs (p. 133). 
Halec >psis (p. 133). 
Scomhroclnpea (p. 135). 
Diplomystns (p. 139); 
Clupea fp. 146). 
