ELOPID^. 
29 
displaying suborbitals, the plate above the operculum, and 
part of the gular plate. 
Presented hy the Hon. Pohert Marslmm.^ 1877. 
P. 9189. Smaller and more imperfect head with abdominal region, 
showing enlarged scale above pectoral fin. 
History unJenown. 
15486. Still smaller head and remains of trunk. 
Purchased from Mr. Gardener. 
47900. Imperfect small trunk in counterpart, the axial skeleton 
noticed loc. cit. p. 537. 
Presented by the Hon. Pohert Marsham, 1877. 
P. 1962 c, P. 3986 a. Small head and abdominal region in counter¬ 
part, doubtfully of this species. 
Egerton EnnisTcillen Colls. 
P. 274. Portion of small trunk in counterpart, doubtfully of this 
species, showing scale-ornament. 
Transferred from Museum of Practical Geology, 1880. 
The following specimen seems to belong to Notelops, but its 
generic determination is unnertain :— 
47899. Fine large trunk, in counterpart, showing portions of all 
the fins. Presented hy the Hon. Robert Marsham, 1877. 
Genus RHACOIjIIPIS^ Agassiz. 
[Edinb. N^ew Phil. Journ. vol. xxx. 1841, p. 83 {Phacole^is')?^ 
Trunk somewhat laterally compressed; abdomen flattened or 
rounded. Parietal bones small and separated by the supraoccipital; 
no deep depression in hinder part of frontal region; gape of mouth 
extending to the hinder border of the orbit; a single supramaxillary 
bone ; margin of the jaws with a single series of small conical 
teeth. Operculum simple; branchiostegal rays about 20 in 
number. Yertebral centra slightly constricted, smooth or delicately 
striated, perforated for the passage of a remnant of the notochord. 
Pectoral fin with a large and elongated scale at its base ; dorsal fin 
more or less directly opposed to the pelvic pair; anal smaller than 
the dorsal fin ; caudal fin deeply forked. Scales usually ornamented 
with delicate radiating ridges; a few very small, thin scales 
extending over the caudal fin ; lateral line inconspicuous. 
The gular plate in this genus has not yet been clearly observed. 
