28 
ACANTHODII. 
Genus C3LIMATIUS, Agassiz. 
[Poiss. Poss. Y. G. R. 1845, p. 119.] 
Syn. Br achy acanthus, Sir P. Eger ton, Rep. Brit. Assoc. 1859 (1860), 
Trans. Sect. p. 116. 
Euthacanthus, J. Powrie, Quart. Journ. Geol. Soc. vol. xx. 1864, 
p. 425. 
Body fusiform, laterally compressed. Teeth minute or absent. 
Fin-spines extremely robust, marked with coarse longitudinal 
ridges, sometimes with posterior denticles; first dorsal spine not 
excessively elongated ; several pairs of free spines on the ventral 
aspect between the paired fins. 
A detached fin-spine only was known to Agassiz, and the precise 
definition of the genus was first rendered possible by Egerton’s 
discovery of C. scutiger. 
Climating reticulatus, Agassiz. 
1845. Climatius reticulatus , L. Agassiz, Poiss. Foss. V. G. R. p. 120, 
pi. xxxiii. fig. 26. 
1861. Climatius reticulatus, Sir P. Egerton, Figs. & Descrips. Brit. 
Organic Remains (Mem. Geol. Surv.), dec. x. p. 68, pi. viii. figs. 
11-13. 
1864. Climatius reticulatus, J. Powrie, Quart. Journ. Geol. Soc. vol. xx. 
p. 421. 
1870. Climatius reticulatus , J. Povrrie, Trans. Edinb. Geol. Soc. vol. i. 
p. 295, pi. xiii. fig. 10. 
Type. Detached fin-spine. 
The type species, attaining a maximum length of about 0*2. 
Body elongated, the greatest depth being contained probably more 
than five times in the total length ; head and branchial apparatus 
occupying one fourth of the total length. Spines all short and broad, 
the longitudinal ridges being more or less tuberculated, and the 
transverse lines of growth at the base usually prominent. Pectoral 
fin-spines the largest and most elongated, considerably arched, 
without posterior denticles ; four pairs of very short and broad, 
small, intermediate, ventral spines, of which the hindermost pair is 
the largest; pelvic fin-spines less than half as large as the pectoral. 
First dorsal spine shorter, broader, and more curved than the second, 
situated midway between the pectoral and pelvic pairs; second 
dorsal spine comparatively straight, slender, and pointed, similar to 
the anal, and either directly opposed to the latter or immediately in 
advance of it. Scales relatively large, smooth, or tuberculated. 
Form. 6,' Loo. Lower Old Red Sandstone : Forfarshire. 
