572 
ACTINOPTERYGII. 
Gymnodus, E. Delfortrie, Actes Soc. Linn. Bordeaux, vol. xxviu. 
1871, p.232. 
Progymnodon, W. Dames, Sitzungsb. k. preuss. Akad. Wiss.,. 
pliys.-math. Cl. pt. i. 1883, p. 148. 
Each jaw fused at symphysis ; each with small dental plates 
round the margin and a symmetrical pair of more or less oblique 
piles of plates closely pressed together within. Separate caudal 
fin. Dermal spines erectile, each with two horizontally-extended 
roots. 
Diodon erinaceus, Agassiz. 
1844. Diodon erinaceus, L. Agassiz, Poiss. Poss. vol. ii. pt. ii. p. 274. 
1859. Diodon erinaceus, A. B. Massalongo, Specimen Photogr. Aniffl. 
Foss. Agr. Veron. p. 21, pi. xii. fig. 2. 
1876, Diodon erinaceus, E. Bassani, Atti Soc. Veneto-Trent. Sci. Nat. 
vol. iii. p. 189. 
Type. Imperfect fish ; British Museum. 
A small species, attaining a length of about O'l . Not precisely 
definable, but dermal spines small and rather sparse, most com- 
paratively short and stout. 
Form. 6f Loc. Upper Eocene : Monte Bolca, near Verona. 
P. 3873. Type specimen, exposed from ventral aspect. The den 
tition is much obscured, and no fins are seen except part 
of the caudal. The largest and most slender spines are 
at the sides of the middle of the trunk. , 
Enniskillen Co U. 
Diodon scillse, Agassiz. 
[Text-figure 20.] 
1844. Diodon scillce, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p- 274. 
1850. Megalurites nitidum, 0. G. Costa, Atti Accad. Pontan. vol. v. 
p. 370, pi. x. figs. 1-4. 
1873. Diodon scillce, G. Guiscardi, Atti R. Accad. Sci. Napoli, vol. v . 
no. 10, with plate. 
1879. Diodon, A. L. Adams, Quart. Journ. Geol. Soc. vol. xxxv. 
p. 529. 
1889. Diodon scillce, A. Portis, Boll. R. Comit. Geol. Ital. vol. xx. 
p. 356. 
Type. Inner dental plates ; British Museum. 
A large species known only by the inner dental plates, which are 
of the form represented in the accompanying fig. 20. At e as 
20 plates in complete pile. Type species of so-called Megalurites, 
