34 
AGAXTHODII. 
Parexus Incurvus, Agassiz. 
1845. Parexus incurvus, L. Agassiz, Poiss. Foss. V. G. R. p. 120, pi. 
xxxiii. figs. 26, 27. 
1864. Parexus incurvus, J. Powrie, Quart. Journ. Geol. Soc. vol. xx. 
p. 424, pi. xx. fig. 1. 
1870. Parexus incurvus, J. Powrie, Trans. Edinb. Geol. Soc. vol. i. 
p. 293, pi. xii. fig. 8. 
Type. Imperfect first dorsal fin-spine. 
The type species, attaining a maximum length of about 0*16, but 
usually much smaller; head occupying one fourth of the total length. 
Fin-spines with crenulated ridges. Pectoral fin-spines short, stout, 
and curved; not less than four pairs of short and broad, small, 
intermediate ventral spines; pelvic fin-spines about two thirds as 
long as the pectorals, much less robust. First dorsal spine straight 
or only slightly curved, at least half as long as the complete fish, 
situated immediately above the pectoral arch, with few, widely 
spaced, upwardly directed, posterior denticles ; second dorsal spine 
about one third as long as the first, placed immediately in advance 
of the anal, which it somewhat exceeds in size. Scales externally 
tuberculated. 
In this species the first dorsal fin is shown to be very small in 
proportion to the size of the spine, while the second dorsal fin 
extends to the apex of its spine. 
Form. Sf Loc. Lower Old Red Sandstone : Forfarshire. 
38593. Contorted fish, showing portions of all the fin-spines and the 
second dorsal and caudal fins ; Turin Hill, near Forfar. 
Presented by James Powrie, Esq., 1864. 
P. 127. Imperfect small fish, wanting the caudal fin; Turin Hill. 
The ornamentation and posterior denticles of the first 
dorsal spine are well exhibited. Purchased, 1880. 
P. 1338. A specimen nearly similar to the last, and a more imper¬ 
fectly preserved fish, displaying the dermal scales and 
plates of the head ; Turin Hill. Egerton Coll. 
P. 1339-40. Three imperfect impressions of the first dorsal spine; 
Farnell. Egerton Coll. 
Parexus faleatus, Powrie. 
1870. Parexus falcatus, J. Powrie, Trans. Edinb. Geol. Soc. vol. h 
p. 294, pi. xiii. fig. 9. 
Type. Well-preserved fish; collection of James Powrie, Esq., 
Reswallie. 
