The so-called Coprolites of Ichthyosaurus, etc. 541 



presence in the abdominal region of 

 the numerous small skeletons of 

 Ichthyosauri, which, together with 

 many large skeletons of Ichthyosauri 

 and Plesiosauri, have been found in 

 the cliffs at Lyme, and supplied to 

 various collectors by the skill and 

 industry of Miss Mary Anning. 

 I have two of these skeletons, in 

 each of which the Coprolites are 

 very apparent, hut flattened." The 

 last remark (here italicized) is 

 especially noteworthy, because it is 

 evident that Buckland himself had 

 not observed the spirally-marked 

 form actually within the skeleton. 

 As proved by his figures in the 

 JBridgewater Treatise (pis. xiii, xiv), 

 he had only seen the same kind of 

 partially digested food which often 

 occurs in well-preserved specimens. 

 In the Lower Lias of Lyme Regis, 

 indeed, the remains of large sharks 

 {Hybodus and Acrodus) are as abun- 

 dant as those of marine reptiles. 

 I am therefore inclined to refer the 

 problematical coprolites to these 

 fishes, in which they would be 

 normal, rather than to the Ichthyo- 

 saurians, in which they would be 

 abnormal. Professor Eberhard Praas 

 has already arrived at the same con- 

 clusion in his well-known work on 

 Ichthyosauria. 1 He points out that 

 the spirally-marked coprolites do 

 not always occur in the same deposits 

 as the Ichthyosaurian skeletons, and 

 that most of them, at any rate, 

 probably belong to fishes, especially 

 Selachians. That the short intestine 

 with a spiral valve has always 

 characterized the sharks is shown 

 by its beautiful preservation in a 

 specimen of the Devonian Clado- 

 selache in the British Museum, drawn 

 in Plate XXXIV. Here there can 

 be no doubt about the interpreta- 

 tion of the appearances in the fossil, 

 such as exists in reference to one 



1 E. Fraas, Die Ichtliyosaurier der silddeutschen Trias- und Jura-Ablage- 

 ungen, p. 34 (Tubingen, 1891). 



