386 MEMOIRS OF THE CARNEGIE MUSEUM. 



Type. — Nearly complete fish; Museum of Natural History, Paris. 



The occurrence of this species in the Lithographic Stone of Cerin, France, is 

 reported by ThioUiere in the faunal list included in his posthumous work of 1873. A 

 considerable number of small and indistinct impressions which may be referred 

 to this species, or may be the fry of some other Leptolepid, are contained in the 

 Bayet Collection. A slab in which several are to be seen has already been spoken 

 of in connection with a specimen of (Eonoscopus elongatus (No. 4088), which appar- 

 ently contains one of the small fry inside. 



27. Leptolepis dubia (Blainville) . (Plate LI, Fig. 1). 

 1818. Clupea dubia H. D. de Blainville. 



Nouv. Diet. d'Hist. Nat., Vol. XXVII, p. 331. 

 1833-44. Leptolepis dubius L. Agassiz. 



Poiss. Foss., Vol. II, Pt. I, p. 13; Pt. II, pp. 134, 294 (in part). 

 1895. Leptolepis dubius A. S. Woodward. 



Cat. Foss. Fishes Brit. Mus., Pt. Ill, p. 509, pi. XIV, figs. 6, 7. 



Type. — Nearly complete fish; Museum of Natural History, Paris. 



This is a large and robust species, attaining a length of about 30 cm., and very 

 abundant in the Lithographic Stone of Bavaria. It has not hitherto been reported 

 from other localities than in the neighborhood of Solenhofen and Eichstadt, but 

 there is one example in the Bayet Collection of the Carnegie Museum which is 

 evidently referable to this species, and is figured in the accompanying plates. It 

 is from the Upper Jura of Cerin, France, and, together with the smaller species 

 of the same genus, serves to illustrate the close correspondence existing between the 

 faunse of the respective localities. The figured specimen is cataloged as No. 4396. 



Genus Thrissops Agassiz. 

 "Head small and teeth minute; sclerotic ossified. Maxilla arched, with a 

 slightly convex dentigerous border; mandible prominent, the dentary apparently 

 intermediate in form between that of Leptolepis and JjJthalion. Opercular ap- 

 paratus as in Leptolepis. Vertebral centra well ossified, strengthened by a median 

 lateral ridge; the free neural arches in the abdominal region much elongated and 

 thickened, the ribs also especially robust. Pelvic fins much smaller than the 

 pectorals ; dorsal fin small and short-based, opposite to the anal fin, which is acuminate 

 in front, and much extended behind; caudal fin forked. Scales completely covering 

 the trunk; no enlarged or thickened ridge-scales." (A. S. Woodward, I. c, Pt. 

 Ill, p. 521). 



