NO. 2177. FOSSIL FISHES IN NATIONAL MUSEUM— EASTMAN. 285 



F. FISHES OF THE JURASSIC SYSTEM. 



There are a number of well-preserved specimens of ganoid fishes 

 in the collection from the Lias of Lyme Regis, Dorsetshire, the Lias 

 of Holzmaden, Wiirttemberg, the Upper Jurassic Lithographic lime- 

 stone of Solehhofen, and a few types, chiefly of Pliolido'pJiorus, des- 

 cribed by the present writer from the Jurassic of the Black Hills, 

 South Dakota. Some of the larger and more interesting specimens 

 from Solenhofen (Squatina, Gyrodus, AspidorhyncTius, etc.) are to be 

 seen on exhibition in the hall of fossil vertebrates. 



In contrast to the large and attractive specimens of the usual type 

 with which we are familiar from the Solenhofen locality, two small 

 forms, evidently juvenile, call for special notice, being in each case 

 the only known example of the young of the species represented. 

 These are described in the following paragraphs. 



Family ASPIDORHYNCHIDAE. 

 The most recent discussion of the structural organization of typical 

 members of this family is that of Paul Assmann, in the first volume 



Fig. 8.— AspiDORHYNCHus ACUTiROSTKis Agassiz. Upper Juka (lithographic stone), Solenhofen, 

 Bavaria. Lateral aspect of cranium, x% (after P. Assmann. ang, angulake; d, dentary; 

 /.frontal; iop, interoperculum; j, jugal; Z, lachrymal; m, maxillary; mcth, mesethmoid; n, 

 rostrum; oc. sup., supeaoccifital; cp, operculum; p,parietal; 7M(Z,predentaey; -prf, prefrontal; 

 prm, premaxillary; ptf, postfrontal; prop, preoperculum; sang, surangulare; sop, suboper- 



CULUM. 



of Archiv fur Biontologie, 1906 (pp. 51-79). It deals chiefly with 

 the type species, A. acutirostris Agassiz (text fig. 8). The anatomy 

 of the allied genus Belonostomus has been carefully investigated by 

 Dr. Benjamin Vetter ^ and some well preserved examples belonging 

 to the Carnegie Museum have recently been figured by the present 

 writer.^ 



J Vetter, B. Die Fische aus dem lithographischen Schiefer im Dresdener Museum. Mittheil. Kon. Min- 

 eral.-Geol. Prsehist. Museum Dresden, pt. 4, 1881. 



2 Memoirs Carnegie Museum, vol. 6, Kos. 6 and 7, 1914-15. The plates for these two publications, and 

 also those for Memoir No. 5 of the same volume, were printed without proofs having been submitted to the 

 author; and in the case of one of the illustrations, that of Squatina minor, the original drawing, which is 

 misleading, was not prepared under his direction. 



