372 MEMOIRS OF THE CARNEGIE MUSEUM. 



In Part I of ThioUiere's Poissons Fossiles de Bugey, p. 23, diagrams are given 

 showing the complete dentition of this species. Several examples of the detached 

 upper and lower dental plates, perhaps referable to this species, are preserved in 

 the collection of the Carnegie Museum, and the most perfect of these is shown of 

 the natural size in the accompanying text-figure. 



Fig. 2. Detached splenial dentition of a Pycnodont fish from Cerin, France, provisionally re- 

 ferred to Microdon itieri Thioll. X 1/1. Cat. No. 4241. 



Family EUGNATHID^. 

 " Trunk fusiform or elongate, not much laterally compressed. Cranial and 

 facial bones moderately robust, externally enamelled, and opercular apparatus 

 complete; mandibular suspensorium nearly vertical or inclined backwards and 

 gape of mouth wide; snout not produced; premaxillse in contact mesially and 

 usually separate ; marginal teeth conical, and larger than the inner teeth. Notochord 

 usually persistent, the vertebrae rarely more than incomplete rings. Fin-rays robust, 

 articulated, and divided distally; fulcra conspicuous. Dorsal fin short and acu- 

 minate. Scales rhombic, sometimes with rounded postero-inferior angle." (A. S. 

 Woodward, I. c, Pt. Ill, p. 285). 



Genus Caturus Agassiz. 

 " Trunk elongate-fusiform. External head-bones and opercular bones feebly 

 ornamented with rugse and tuberculations, all except the cheek-plates robust; 

 snout obtusely pointed, and maxilla straight or with a slightly concavely-arched 

 dentigerous border; teeth relatively large and arranged in a sparse series on the 

 margin of the jaws; smaller on the palatine and on the splenial, where they are in 

 single series anteriorly, minute and almost granular on the other inner bones; 

 preoperculum nearly smooth and narrow; operculum deep, much broader below 

 than above, and suboperculum of moderate size. Ossifications in the sheath of 

 the notochord insignificant or absent in the smaller species, consisting only of 

 separate hypocentra and pleurocentra in the largest species; ossified ribs slender, 

 not reaching the ventral border of the abdomen. Fulcra biserial, well-developed 

 on all the fins, those of the pectoral being especially elongated and sometimes in 

 part fused together. Pectoral much exceeding the pelvic fins in size, but the 



