﻿Vol. 64.] FROM THE CEETACEOTTS FOEMATIOX OF BAHIA. 359 



specimen, and the dorsal fins are replaced nearly in the natural 

 position in PI. XLII, fig. 1. The neural and hsemal arches of the 

 axial skeleton immediately in advance of the tail are remarkably 

 long and slender, with a gentle curvature. From sixteen to 

 eighteen vertebral segments, with stout arches and appended axou- 

 osts, support the principal part of the caudal fin ; and there are 

 remains of a few terminal slender rays which may indicate the 

 presence of a supplemental caudal fin. The anterior dorsal fin (d^) 

 comprises eight stout rays, of which the right and left halves are 

 loosely apposed and sometimes slightly displaced in the fossil. 

 These rays, which are quite smooth and show no traces of denticles, 

 are all undivided in their basal two-thirds, but finely articulated 

 distally; and they gradually decrease in size" backwards, so that the 

 hindmost is only half as long as the foremost ray. The finis directly 

 supported by the usual thin plate of bone, the proximal end of 

 which is lacking in the fossil. .The posterior dorsal fin (d~) is crushed 

 and distorted, but is evidently somewhat smaller than the anterior 

 dorsal, with much more slender and more extensively articulated 

 rays. Its laminar support, as usual, is forked below, with the 

 stouter limb inclined forwards. The anal fin (a), which disi^lays 

 its lobate character, resembles the posterior dorsal, but is somewhat 

 smaller. It comprises about twenty rays, which are closely arti- 

 culated for more than half of their length. The rays of the principal 

 caudal fin are Yeiy stout and pressed close together, but they 

 cannot easily be counted, because their right and left halves are 

 loose and partly displaced. Their total number is about 16. These 

 rays are quite smooth, without any trace of denticles ; they are all 

 closely articulated distally for less than half of their length. There 

 are no remains of scales, but various fragments of smooth plates are 

 probably referable to the air-bladder. 



The small fish now described differs specifically from Mawsonia 

 gigas in the rounded shape of the coronoid process of the angular 

 bone, and in the finely- striated ornament of the operculum ; so that 

 it may be named Maivsonia minor. Its chief interest, however, 

 depends on the fact that it exhibits for the first time several of the 

 characters of the trunk and fins of the genus to which it belongs. 

 It is now clear that Maivsonia differs from all known Jurassic and 

 Cretaceous Coelacanths in lacking denticles on the fins. It is also 

 probable that the fish was scaleless, for the condition of the type- 

 specimen is such that at least some of the ridges or denticles of the 

 scales should have been preserved if they had been originally 

 present. 



Lepidotfs Souzai, sp. nov. (PI. XLIII, figs. 1 & 2.) 



A new species of Lepidotus is represented by part of a head 

 (P]» XLIII, fig. 1), and by the crushed and partly-scattered remains 

 of a nearly complete fish, which cannot have measured less than a 

 metre in length. It is a short and stout species, probably much 

 like the Wealden L. ManteUi in proportions, and is remarkable for 

 the very prominent ornamentation of its external bones and scales. 



