NO. 2177. FOSSIL FISHES IN NATIONAL 2IUSEVM— EASTMAN. 281 



culum, but the preoperculiim was probably much reduced and nearly 

 concealed by adjacent elements. 



Formation and locality. — Upper Trias; Connecticut Valley and 

 New Jersey. 



Family BELONORHYNCHIDAE Woodward. 



Of this family of Triassic chondrosteans, only a single genus which 

 is capable of satisfactory deimition has hitherto been discovered. 

 This is Belonorhynchus, represented by about a dozen species. Under 

 the term of Sauriclitliys Agassiz are provisionally included several 

 species which may be generically identical with Belonorhynchus, as 

 suggested by Otto Reis/ but for the present, following Woodward's 

 example, it seems preferable to retain the estabhshed systematic 

 arrangement. 



Two representatives of Belonorhynchus have been described byA.S. 

 Woodward from the Upper Trias of Gosford, New South Wales. 

 These have been named B. gigas and B. gracilis, and differ from other 

 known species in the form of dermal scutes and minor details of the 

 fins and scales. From the same horizon and locahty a single very 

 pecuhar specimen has been obtained which recalls in some respects, 

 such as body contour and character of the remote dorsal fin, the smal- 

 ler of these species (B. gracilis). But the conformation of the head 

 and obtuse, romided snout does not agree at all with the features 

 which we are accustomed to associate with members of this genus for 

 the corresponding region; and the specimen in question is clearly 

 anomalous in this regard. 



The specimen just referred to belongs to the Museum collection, 

 and is shown in plate 14, figiu-e 3. It is embedded in the same slab of 

 sandstone in which are contained several specimens of Cleithrolepis. 

 Semionotus, and Dictyopyge, the whole block being entered under the 

 catalogue number 1842. Unfortunately the condition of the speci- 

 men does not permit of a closer identification than to suggest being 

 included as an aberrant representative of the Belonorhynchidae, with 

 much abbreviated snout. Sutures in the cranial shield are not dis- 

 tinguishable, and it would appear as if the actual bone substance had 

 been fractured and exposed to weathering. Under such circum- 

 stances we are not warranted in estabhshing a new genus or species 

 upon the evidence of the solitary specimen before us, but a figure of 

 it is given in the hope that further enhghtenment may be at some 

 later time forthcoming. 



1 Geogn. Jahresb., 1891, p. 149, 



