XXI MALACOPTERYGII 545 
3. Interopereculum normal ; basis cranii simple. 
Maxillary large, toothed ; praecaudal vertebrae without well-marked parapo- 
physes ; scales cycloid or absent ; adipose dorsal fin present or absent 
19. Stomiatidae. 
Mouth small, toothless ; vertebrae with strong parapophyses ; head and body 
covered with spiny scales ; f : . 20. Gonorhynchidae. 
Mouth small, toothless ; no symplectic ; head and body naked 
21. Cromervidae. 
Fam. 1. Pholidophoridae.— Margin of the upper jaw formed 
by the praemaxillaries and the maxillaries, the latter large and 
loosely attached; teeth small and conical. Parietal bones separ- 
ating the supraoccipital from the frontals ; opercular bones well 
developed. Vertebral centra never advanced beyond the annular 
stage ; ribs delicate; no fused or expanded haemal arches at the 
base of the tail; no epipleurals or epineurals. Fin-fulera present, 
but usually small; dorsal and anal fins small, the former above or 
behind the ventral fins, which are small or may be absent. Scales 
ganoid, rhombic, those on the flanks united by peg-and-socket 
joints. 
This family, which appears to me to be related to the 
Dapediidae, is provisionally placed here by A. 8S. Woodward on 
account of its resemblance to the Leptolepididae, but it is not yet 
quite clear that the mandible was destitute of splenial and coronoid 
elements, while the bones at the base of the pectoral fin have not 
hitherto been observed. The principal genera are Pholidophorus, 
ranging from the Upper Trias to the Purbeck; Zhoracopterus, 
from the Upper Trias ; and Plewropholis, from the Upper Jurassic. 
The species of Pholidophorus are very numerous in the Jurassic 
period, and Woodward has observed that the scales of the later 
species are more elaborately ornamented than those of earlier date. 
Fam. 2. Archaeomaenidae.— Distinguished from the pre- 
ceding by the thin, cycloid scales. Conspicuous obtuse ridge- 
scales are present along the dorsal and ventral lines. Archaeomenes, 
from the Jurassic (?) of New South Wales. 
Fam. 3. Oligopleuridae.—Characters as in Pholidophoridae, 
but scales cycloid and vertebrae completely or nearly completely 
ossified. 
Oligopleurus, from the Jurassic of England and France ; 6”. 
scopus, from the Jurassic and Cretaceous of Franee, Germany and 
Italy; and Spathiurus, from the Cretaceous of Mount Lebanon 
and Dalmatia. 
VOL. VII 2N 
