400 
ACTION 0 ITER YGII. 
pt. i. (1866), p. 183, pi. ii. fig. 3; W. Deecke, Palas- 
ontogr. vol. xxxv. (1889), p. 126.—Upper Trias ; Raibl, 
Carinthia. [Museum of Imperial Geological Survey, 
Vienna.] 
Prohalecites porro, W. Deecke, loc. cit. p. 125, pi. vii. figs. 5-7. 
Pholidophorus porro , C. Bellotti, in A. Stoppani, Studii 
Geol. e Paleont. Lombardia (1857), p. 430; 0. G. Costa, 
Ittiol. Loss. Ital. (1873), p. 65, pi. v. fig. 9.—Upper 
Trias ; Perledo, Como. [The type species of Prohalecites . 
Milan Museum.] 
Either to the Pholidophoridae or to the Leptolepidae may also 
probably be referred the unique fragmentary fossil described as 
follows :— 
Megalopterus raiblianus , R. Kner, Sitzungsb. k, Akad. Wiss., 
rfseov*. /3<rre'2f2£ math.-naturw. Cl. vol. liii. pt. i. (1866), p. 174, pi. iv. 
/S/b 1.—Upper Trias; Raibl, Carinthia. [Imperfect 
hi &+/*' caudal region ; Imperial Geological Survey Museum, 
&/.*&■** Vienna. The type species of Megalopterus.'] 
Family OLIGOPLEURKUE. 
Trunk fusiform. Head with delicate membrane-bones, scarcely, 
if at all, enamelled; mandibular suspensorium nearly vertical or 
inclined forwards, and gape of mouth wide; teeth small or of 
moderate size. Vertebral centra well-ossified, with no distinct 
pleurocentra and hypocentra in any part of the column: large free 
neural spines in the abdominal region ; ribs short; no fused or 
expanded haemal arches at the base of the tail. Intermuscular 
bones rare or absent. Fin-fulcra present; dorsal and anal fins 
acuminate in front, of variable length. Scales thin, more or less 
rounded, and deeply imbricating. 
Synopsis of Genera. 
I. Dorsal fin short-based. 
Vertebral centra not pitted ; mandible pro¬ 
minent; dorsal opposed to anal fin. Oligopleurus (p. 491). 
Vertebral centra with two lateral pits; man¬ 
dible not prominent; greater portion of 
dorsal in advance of anal fin. Oeonoscopus (p. 494). 
II. Dorsal fin extended. 
Vertebral centra with two lateral pits ; fulcra 
on all fins; anal fin short, opposed to 
hinder end of dorsal; caudal fin forked . . Spathiurus (p. 498). 
