252 Messrs. Hancock and Attliey on two 



they are coarsely punctate, and covered with a stout, highly 

 polished enamel. 



We are thus assured that Pleurodus is a Cestraciont ; and 

 such being the case, its small size is very remarkable. But it 

 must be mentioned that if the large teeth are mere varieties of 

 the small and usual form, then our specimen may not by any 

 means be fully grown ; however, after making every allow- 

 ance for increase in size on this account, still the species 

 would be a very small Cestraciont, most of which are of con- 

 siderable dimensions. Wodnika, which is a small species, 

 judging from Munster's figure*, cannot have been less than a 

 foot long. It is nevertheless quite possible that our specimen 

 is, notwithstanding, a fully developed individual. This is ren- 

 dered probable by the fact that the teeth in connexion with it 

 are of the usual size of those found detached at Newsham ; and 

 of such we possess thirty or forty : some of these are smaller 

 than those connected with the specimen ; scarcely any are 

 larger ; or if so, there is a mere shade of difference in this 

 respect. In the separate head before alluded to, the teeth are 

 likewise of the usual size ; and the second or detached spine 

 already mentioned is not quite so large as that in connexion 

 with the fish. 



Platysomus rotundus^ n. sp. 



A very distinct and beautiful species of Platysomus has 

 occurred at Newsham 5 three almost perfect specimens of it 

 have been met with, and four or five considerable portions, all 

 of which exactly agree in character, though they vary a little 

 in size. The largest and most perfect specimen is three inches 

 long, measured from the clavicle to the end of the tail-iin, 

 and is two inches and three quarters deep at the widest part. 

 It is in a fine state of preservation ; the contour is perfect, 

 with the exception of that of the head, which is moderately 

 developed in proportion to the body ; the cranial bones, how- 

 ever, are dislocated and thrust a little forward ; but apparently 

 the head would not project much were they restored to their 

 natural positions. The dorsal margin, from the occipital crest 

 to the root of the tail, is regularly and deeply convex ; so is 

 the ventral margin in its whole extent from the clavicle down- 

 wards ,' the body of the fish, including the head, is therefore 

 almost circular. The pectoral fins appear to have been well 

 developed, but they are badly displayed ; the ventrals are also 

 very indistinct, though sufficient of one of them is seen for 

 verification t : the dorsal and anal are well preserved; they 



* Beitrage, Heft vi. p. 48, Taf. 1. fig. \aiod. 



t As the existence of ventrals in Platysomus has been doubted, we take 



