J. H. Cooke — On Stereodon Melitensis. 547 



A portion of the bony skeleton of a fish of the same species was 

 also discovered in the same locality; but as it was not sent with the 

 other specimens, it has been neither figured nor described. 



In the course of his paper Owen repeatedly refers to it, and 

 finally concludes by saying, "It is much to be desired that the rest 

 of the skeleton of this extinct fish should be figured." No attempt 

 has, hitherto, been made to carry out this suggestion, and as no 

 record of this interesting specimen exists, I have therefore visited 

 the Malta Museum, wlierein the fossil is now deposited, and have 

 obtained the following particulars relating to it. 



The specimen is oblong in shape, and measures 22|- inches from 

 the snout to the 10th dorsal vertebra. It consists of a fragment of 

 the head, and a portion of the vertebral column, the latter of which 

 extends as far as the 10th dorsal. 



The vertebrge are circular in shape, and they form a continuous 

 chain which curves slightly in a downward direction. Tliey are 

 well ossified, but, unfortunately, most of them have been badly 

 developed from the matrix, and their characteristic features have 

 thereby been obliterated. The 1st, 2nd, 3rd, and 5th are, however, 

 in an excellent state of preservation ; and the 10th vertebra 

 distinctly shows deep lateral pits longitudinally extended. Each 

 vertebra is bi-concave, and its body is somewhat depressed towards 

 the middle. Compared with the posterior diameter, the antero- 

 posterior diameter is much the shorter of the two. 



Posterior diameter of the 6th dorsal vertebra ... 1^ inches. 



Antero -posterior of the 6th dorsal vertebra ... | of an inch. 



Posterior diameter of the 10th dorsal vertebra ... -| ,, 



Antero-posterior of the 10th dorsal vertebra ... f ,, 



The average diameter of the posterior extremities is 1|^ inches. 



Above and below each of the vertebrae exhibits a broad protuber- 

 ance, which forms the base of a long, sword-shaped spine, the 

 flattened sides of which lie in a plane with the vertebral column, 

 while the thin edges lie in the direction of the articular facets. 

 These spines are anchylosed with the neural and haemal arches of 

 the vertebrge. They avei'age three inches in length, and half an 

 inch in width. The neural spines spring obliquely upwards and 

 backwards from the centrum, while those on the haemal side spring- 

 obliquely downwards and backwards, and gradually become shorter 

 and more slender as the caudal extremity is approached. 



There are no traces of scales. 



Considerable portions of the bones of the head have been pre- 

 served in the limestone matrix, but most of them are so crushed as 

 to be quite unrecognizable. 



A fragment of the left branch of the lower jaw, containing a tooth 

 which is similar in every respect to those that formed the subject of 

 Professor Owen's paper, is intact, and thus affords an opportunity 

 for the comparison of the two fossils. 



Highland House, St. Julian's, Malta. 



