﻿34 ACANTHODII. 



Parexus incurvus, Agassiz. 



1845. Parexus incurvus, L. Agassiz, Poiss. Foss. V. G. R. p. 120, pi. 



xxxiii. figs. 20, 27. 

 1864. Parexus incurvus, J. Powrie, Quart. Journ. Geol. Soc. vol. xx. 



p. 424, pi. xx. fig. 1. 

 1S70. 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. <$)- Log. Lower Old Eed 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 falcatus, Powrie. 



1870. Parexus falcatus, J . Powrie, Trans. Edinb. Geol. Soc. vol. i. 

 p. 294, pi. xiii. fig. 9. 



Type. Well-preserved fish ; collection of James Powrie, Esq., 

 Reswallie. 



