1S4 Annals of the Carnegie Museum. 



ful preservation of muscle fibers and other soft parts in the Upper 

 Devonian Cladoselache encourages the expectation that further light 

 may be forthcoming respecting the food-habits of that primeval shark. 



Very peculiar conditions have been observed by Campbell Brown 

 in the case of a Liassic shark, Hybodus, which had apparently en- 

 countered a swarm of immature belemnites and proceeded to make a 

 meal of them. In this connection the author states: "Das gefrassige 

 Thier war augenscheinlich in einen dichten Schwarm kleinerer Belem- 

 niten gerathen und hatte sich mit denselben vollgestopft. Bei der 

 Verdauung traten dann Beschwerden ein. Belemnitenrostra sind nicht 

 gerade besonders geeignet, die Spiral ldappe im Colon eines kleinen 

 Haifisches zu passiren, besonders wenn mehrere Hundert zu gleicher 

 Zeit im Magen liegen. Der Tod des Haies kann nicht iiberraschen!" 7 



Among teleostean fishes, it is not uncommon to find specimens 

 showing the particular nature of their stomach contents. The pre- 

 daceous ganoid Caturus, from the Upper Jura of Solenhofen, very 

 often contains recognizable portions of Leptolepis within the ab- 

 dominal cavity. In the Paris Museum of Natural History is pre- 

 served a slab containing two individuals of Blochius, from the Eocene 

 of Monte Bolca, the larger one having apparently partially swallowed 

 the other. Agassiz, however, states that the appearances are decep- 

 tive, and that the two individuals may have chanced to be comesuper- 

 imposed one upon the other in a rather striking attitude. Neverthe- 

 less he remarks: 8 "Je ne pretend pas nier d'une maniere absolue la 

 Dossibilite. d'une pareille coincidence." 



We have now to consider the very singular, if not indeed unique 

 conditions presented by two specimens of Jurassic fishes belonging to 

 the Bayet collection of the Carnegie Museum. The first of these which 

 invites attention is a form, referable to the genus Belonostomus 

 (Plate X), from the Lithographic Stone (Lower Kimmeridgian) cf 

 Cerin, in southeastern France. The species, judging from the slender 

 proportions of the head, in which the snout is greatly elongated, is 

 probably to be identified as B. tenuirostris Agassiz, but it is evidently 

 an immature example, the total length of which probably did not 

 exceed 16 cm. The caudal region is lacking, but the head and anterior 

 part of the trunk are very clearly shown. The scales, cranial and 



; Brown, C. " Ueber das Genus Hybodus und seine systematischc Stellung." 

 Palaeontogr., 1900, vol. 46, p. 163. 

 8 Agassiz, L. " Poissons Fossiles," 1844, vol. 2, pt. 2, p. 257. 



