156 INTESTINAL STRUCTURE OF FOSSIL FISHES. 



the fossil worm-like bodies, so abundant in the lithographic 

 slate of Solenhofen, and described by Count Munster in the 

 Petrefacten of Goldfuss, under the name of Lumbricaria, 

 are either the petrified intestines of fishes, or the contents of 

 their intestines, still retaining the form of the tortuous tube 

 in which they were lodged. To these remarkable fossils he 

 has given the name of Cololites. (PI. 15', is copied from one 

 of a series that are engraved in Goldfuss. Petrefacten, PI. 

 66.) He has also found similar tortuous petrifactions within 

 the abdominal cavity of fossil fishes, belonging to several 

 species of the genus Thrissops and Leptolepis, occupying 

 the ordinary position of the intestines between the ribs.* (See 

 Agassiz Poissons Fossiles, liv. 2, Appendix, p. 15.) 



It is probable that to many persons inexperienced in ana- 

 tomy, any kind of information on a subject so remote, and 

 apparently so inaccessible, as the intestinal structure of an 

 extinct reptile or fossil fish, may at first appear devoid of 

 the smallest possible importance ; but it assumes a character 

 of high value, in the investigation of the proofs of creative 



* As these Cololites are most frequently found insulated in the litho- 

 gfraphic limestone, M. Agassiz has ingeniously explained this fact by ob- 

 serving the process of decomposition of dead fishes in the lakes of Switzer- 

 land. The dead fish floats on the surface with its belly upwards^ until the 

 abdomen is so distended with putrid gas, that it bursts : through the aperture 

 thus formed the bowels come forth into the water, still adhering together in 

 their natural state of convolution. This intestinal mass is soon torn from 

 the body by the movement of the waves ; the fish then sinks, and the bowels 

 continue a long time floating on the water: if cast on shore, they remain 

 many days upon the sand before they are completely decomposed. The 

 small bowels only are thus detached from the body, the stomach and other 

 viscera remain within it. 



We owe this illustration of the nature of these fossil bodies, whose origin 

 has hitherto been inexplicable, to the author of a most important work on 

 fossil fishes, now under publication at Neuchatel. His qualifications for 

 so great and difficult a task are abundantly guaranteed by the fact, that 

 Cuvier, on seeing the progress he had made, at once placed at the disposal 

 of Professor Agassiz the materials he had himself collected towards a simi- 

 lar work. 



