362 
ACTJNOPTEE’iIGTT. 
Rhamphognathus sph3rr8enoides (Agassiz). 
1796. Silurus hagres, G. S. Volta, Ittiolit. Veronese, p. Ixx. pi. xiv. 
fig. 3 {errore). 
1796. Esox sphyr(Bna,(ji. S. Volta, ibid. p. cvii. pi. xxiv. fig. 3 {errore). 
1818. Esox spret, H. D. de Blainville, Nouv. Diet. d’Hist. Nat. 
vol. xxvii. p. 341 {errore). 
1818. “ Silu?’i(s bagre,'^ H. D. de Blainville, ibid. p. 343. 
1835-44. Mesogaster sp/njrcenoides, L. Agassiz, Neues Jahrb. 1835, 
p. 292 (name only), and Poiss. Foss. vol. v. pt. i. p. 105, pi. xxxviii. 
figs. 2, 3. 
1876. Mesogaster sphyreenoides, F. Bassani, Atti Soc. Veneto-Trent. 
- ScLNat. vol. iii. p. 187. 
Type. Imperfect fish ; Paris Museum of Natural History. 
The type species of the so-called genus Mesogaster, attaining a 
length of about 0*2. Length of head with opercular apparatus 
contained about three and a half times, and maximum depth of 
trunk about seven times in the total length of the fish. Premaxillary 
border apparently straight and teeth very minute. Vertebrae about 
18 in the abdominal, 22 in the caudal region. Pelvic fins arising 
somewhat nearer to the pectorals than to the anal. Anterior 
dorsal fin, with six slender spinous rays and the third the longest, 
arising opposite a point just behind the pelvic pair; space between 
the two dorsal fins about equal to that between the origin of the 
posterior dorsal and the caudal, and this space exhibiting a series 
of ten free fin-supports; posterior dorsal and anal fins equal and 
directly opposed, each with nine or ten rays, the foremost being a 
short spine. 
Form. Log. Upper Eocene : Monte Bolca, near Verona. 
P. 5128. Fine specimen about 0’2 in length, showing all the 
generic and specific characters mentioned above except 
the minute teeth. The straight cleft of the mouth clearly 
extends as far as the orbit. Bemains of a small un¬ 
digested fish are observed in the abdomen. 
Purchased, 1886. 
28437. Somewhat smaller distorted specimen with very imperfect 
head. Purchased, 1853. 
The so-called Rhamphognathus verneuili (F. de Botella, Descrip. 
Geol. Murcia y Albacete, 1868, pi. xi. fig. 5), from Lorca, Spain, is 
an indeterminable fragment. 
Mesogaster cretaceus (W. von der Marck, Palmontogr. vol. xxxi. 
