SCOMBEID^. 
463 
which attains a length of about 0*2. Length of cranium equalling 
twice its maximum width; fossae on cranial roof for lateral muscles 
not extending forwards beyond hinder border of orbit; maximum 
depth of mandible less than one third its length; superficial rugosity 
on cranial roof and dentary comparatively coarse. Teeth well 
spaced, not very variable in size. 
Form. ^ Log. Lower Eocene (London Clay) : London Basin. 
P. 4145. Fine head, considerably larger than the type specimen ; 
Sheppey. Enniskillen Coll. 
P. 4144. Abraded large head, labelled by Agassiz ; Sheppey. 
Enniskillen Coll. 
28758. Head, wanting occipital region ; Sheppey. 
Purchased^ 1853. 
P. 1756. Imperfect rostrum of smaller skull; Sheppey. 
Egerton Coll. 
37759. Cranium; Sheppey. Saull Coll. 
38920, 38943. Two imperfect crania; Sheppey. Bowerhank Coll. 
P. 166. Cranium, broken across middle ; Sheppey. 
Purchased, 1880. 
28713, 28759. Three imperfect occipital halves of cranium; 
Sheppey. Purchased, 1853. 
43107. Similar specimen; Sheppey. Wether ell Coll. 
P. 9480. Similar specimen; Sheppey. Enniskillen Coll. 
P. 1757. Two more imperfect crania ; Sheppey. Egerton Coll. 
P. 7382. Fragmentary hinder portion of cranium, derived from 
London Clay ; Bed Crag, Waldringfield, Sufiblk. 
Prestwich Coll. 
P. 8985. Similar specimen; Coralline Crag, Sutton, Suffolk. 
Presented by Lady Prestwich, 1896. 
Genus AUXIS, Cuvier. 
[Begne Animal, ed. 2, vol. ii. 1829, p. 199.1 
Trunk elongate-fusiform ; the slender caudal pedicle with strong 
median lateral keel. Teeth minute and conical on margin of jaws, 
none on palatines, rare on vomer ; gill-rakers long, slender, and 
numerous. Vertebrae 30 to 40 in total number; the centra much 
