278 
ACriNOPTKKYGH. 
denticles on the scales is seen immediately behind tl 
anal fin. Noticed in 1’roc. Zool. Soc. 1896, p. o04. 
History unknown. 
Notogoneus longiceps (Meyer). 
[Plate XV. fig. 5.] 
1844. Cobit, is tongioeps, L. Agassiz, Poiss. Foss. vol. v. pt- x - P' 
(name only). _ , x> 
1848. Cobitis longiceps, H. von Meyer, Palscontogr. vol. i. p- U* ;P 
fig. 2. 
Type. Imperfect fish. ^ Length 
A small slender species, attaining a length of about 0-1-. e 
of head with opercular apparatus about twice as great a ^ 
maximum depth of the trunk and occupying slightly loss t 
third of the total length to the base of the caudal fin. ' ' v 1 ^ j v ; c 
in suboperculura. Dorsal fin arising immediately behind ' ' een 
pair ; anal fin comparatively small, arising nearly midway )( 
the pelvic pair and the caudal fin. 
Form. <Sf Loc. Upper Oligocene : Mayence Basin. 
P.7667. Imperfect distorted large specimen; Monabacb, 
Mayence. There are indications of the scales ex e^ ^ 
over the cranium ; and the characteristic c e 
observable in the hinder border of the subopereu um 
Purchased, 
15674. Imperfect smaller specimen; Mombach. tn orders, 
centra are shown to be slender constricto cj 
which must have been pierced by a rather stou r s ^ 
of the notochord. About 12 rays can be countu^^^^ 
dorsal, 9 in the anal fin. 
P. 1820. Partly distorted fish, shown of the natural size in F j ft 
fig. 5 ; Mombach. The long and narrow cram ^ . g 
exposed from above ; while the smallness o r t,icul» r 
indicated by the position of the quadrate a,lf ! lfe| . part 
end of the mandible preserved beneath. I he »y ie ' J g ; 0 n. 
of the characteristic maxilla is shown in | ace d, 
The opercular apparatus is much crushed an ^ ; s ]j a ble. 
but the fissures in the suboperculum are < ^ s ^"' n var ; ouS ly 
The delicate vertebral axis is well shown, thou n 0 ). oC hord 
fractured; and the extent to which t ? cping the 
persisted is indicated by the calcareous matrix r j|j 9 
constricted vertebral cylinders. The very 0 10 
