NO. 2177. FOSSIL FISHES /.V NATIONAL MUSEUM— EASTAIAN. 287 



Vergleicht man nun damit die f iir Aspidorhynchus typischen Verhaltnisse, welche 

 aus zahlreichen Darstellungeu hinlanglich bekannt sind, so stosst man auf folgende 

 durchgreifende Unterschiede: 1) Die Seitenlinienschuppe erreicht hochstens die- 

 selbe, meistens eine erheblich geringere Hohe als die darunter folgende. 2) Diese 

 schueidet unten wie die erstere mit schiefem Rande ab. 3) Darunter folgt eine mit- 

 telhohe Schuppe, deren hinterer Rand in der Regel langer ist als ihr Langsdurch- 

 messer, una nun erst kommen die niedrigen Ventralreihen. 4) Die iiber der Seiten- 

 linienschuppe stehende Schuppe ist noch ansehnlich hoch und von regelmassigem 

 Umi-iss. 5) Daruber kommen mindestena 3 Reihen rhombischer, durchweg stark 

 sculp tirter Schuppen. 



The scale arrangement in the specimen in hand is not clearly dis- 

 played. On the other hand the head bones, teeth of the maxillary 

 and mandible, vertebral rings with then- fused arches, and aU of the 

 fins, are distmctly visible. The dorsal fin comprises at least 10 rays, 

 and the anal a larger number, apparently about twice as many. 



Formation and locality. — Lower Kimmeridgian (Lithographic 

 Stone) ; Solenhofen Bavaria, The figured specimen is catalogued as 



No. 23. 



Genus NOTAGOGUS Agassiz. 



This genus closely resembles Propterics, bub differs in the non- 

 elongation of the anterior rays of the dorsal fin, which are very 

 widely spaced, and in the less deeply forked character of the caudal fin. 



NOTAGOGUS MINUTUS, new species- 

 Plate 14, fig. 4. 



Founded upon a very small (5 cm. long), nearly complete fish, in 

 which the proportions of head and trunk are very similar to those 

 (Cat. No. 8379, U.S.N.M.) of N. inimontis Thiolhere, but with more 

 slender form of body, the two portions of the dorsal less widely sep- 

 arated, each consisting of about nine rays, and posterior border of 

 scales smooth. 



This is one of the smallest known species of Notagogus, and it is 

 probable that the unique specimen upon which it is founded is an 

 immature individual. At the same time its characters appear toler- 

 ably distinct, and as it camiot be identified as the young of any known 

 form we are warranted in describing it as representing a separate 

 species. Another small form accompanying the holotype in the same 

 horizon is the recently described N. decoraius, in which the anterior 

 portion of the dorsal comprises about 10 rays, all widely spaced with 

 the exception of the first three. N. inimontis is known only from the 

 Cerin locahty in the ancient province of Bugey, France. 



Formation and locality. — Lower IGmmeridgian (Lithographic 

 Stone); Solenhofen, Bavaria. 



Q. FISHES OF THE TERTIARY SYSTEM. 



A rich assortment of fossil fishes from the Green River Eocene of 

 Wyoming and other western locahties is contahied in the collection, 

 and among the number are included several important type speci- 



