130 1CHTHYODORULITES. S%. 
^ <? ^j» 7 j>^. V 
" ' Genus PHYSOWEMUS, M‘Coy. 
[Ann. Mag. Nat. Hist. [2] vol. ii. 1848, p. 117.] 
Syn. Xystr acanthus, J. Leidv, Proc. Acad. Nat. Sci. Philad. 1859, p. 3. 
Drepanacanthus, Newberry & Worthen, Pal. Illinois, yol. ii. 
1866, p. 120. 
Spines much laterally compressed, strongly arched, often hook¬ 
shaped ; base of insertion broad. Sides of exserted portion more or 
less ornamented with tuberculated longitudinal ridges; small den¬ 
ticles present upon the concave edge. 
According to Newberry and Worthen, the form of the inserted 
portion in the so-called Drepanacanthus proves that the spine was 
arched forwards. 
Physonemus arcuatus, M‘Coy. 
1848. Physonemus arcuatus , F. M‘Coy, Ann. Mag. Nat. Hist. [2] 
vol. ii. p. 117. 
1855. Physonemus arcuatus, F. M‘Cov, Brit. Palaeoz. Foss. p. 638, 
pi. iii. i. fig. 29. 
1883. Physonemus arcuatus, J. W. Davis, Trans. Hoy. Dublin Soc. [2] 
vol. i. p. 367, pi. xlvii. fig. 8. 
Type. Woodwardian Museum, Cambridge. 
The type species. 
Form. Sf Loc. Lower Carboniferous Limestone : Armagh and 
Gloucestershire. 
P. 2239. Base of spine: Armagh. Egerton Coll. 
P. 2519. Distal portion of spine; Armagh. This is probably the 
specimen assigned provisionally to Chalazacanthus verru¬ 
cosus by J. W T . Davis, loc. cit. p. 371. Ennislcillen Coll. 
P. 2520-21. Two more imperfect specimens, both “decorticated”; 
Armagh. Ennislcillen Coll. 
38022. Similar specimen ; Black Hock, Bristol. Purchased , 1863. 
Physonemus attenuates, Davis. 
1883. Physonemus attenuatus, J. W. Davis, Trans. Hoy. Dublin Soc. 
[2] vol. i. p. 369, pi. xlvii. fig. 10. 
Type. Formerly in the Enniskillen Collection 1 . 
Form, Loc. Lower Carboniferous Limestone : Armagh. 
1 See Introduction. 
