Coelacanthus lepturus and Ctenodus. 257 



small, short, stout, conical, and obtusely pointed, and seem to 

 be firmly ancliylosed to the bone. 



The dentary bone has apparently been united to the arti- 

 cular piece by a squamose suture ; but, howsoever this may 

 have been, it is evident that the attachment was only slight, 

 as the two bones are frequently found detached. 



The maxillary teeth are well developed ; they are larger 

 than those of the mandible, are stoutish at the base, decidedly 

 recurved and sharply pointed ; but we are unable to determine 

 their number and arrangement, on account of the disturbed 

 condition of our specimens. There are teeth on both the 

 maxillge and prgemaxillffi. In addition to these dental organs, 

 the vomer is armed with close-set, minute, rounded tubercles 

 or teeth. This is undoubtedly the same spatulate dentigerous 

 bone figured and described in the 12th Decade of the Geological 

 Survey by Professor Huxley as the parasphenoid or vomer in 

 Macropoma : in form and position it is very similar. 



Ctenodus J Agassiz. 



The body-scales of Ctenodus are entirely unknown, with 

 the exception of those of C. elegans and C. ohliquus, which we 

 described some time ago* — the former in a good state of pre- 

 servation, the latter in a less perfect condition. We have, 

 however, obtained from time to time numerous fragments of 

 large scales, so frequently associated with the remains of the 

 larger Ctenodontes that we can have little doubt they belong to 

 themf. Among these fragments are four or five which exhibit 

 the greater portion of the contour of the scale, and one which 

 has it almost entire. These are all parallelogramic in form, 



* Ann. Nat. Hist. ser. 4. vol. i. p. 77. 



t As this paper was passing through the press, we obtained complete 

 proof of the truth of this opinion in a fine specimen of the greater portion 

 of a cranium and part of the trunk of a large Ctenodus with the opercular 

 plates attached : a considerable number of the ribs are exhibited in con- 

 nexion with the head, disposed in natural order ; and numerous neura- 

 pophyses and apparently intemeural spines are scattered along the dorsal 

 ridge. Everywhere mixed up with this interesting specimen these pecu- 

 liar scales are found, much broken, indeed, but occupying both sides of 

 the body portion of the fish, in such a manner as to leave no doubt on the 

 subject. The scales are very similar to those described in the text, dif- 

 fering only specifically, the margin being wider ; the smooth central area 

 has the same peculiar minute surface-structure, and the upper surface is 

 minulely granulated in the same manner. Moreover this specimen shows 

 the hatchet-shaped bones, or clavicles, described by us on a former occa- 

 sion, in connexion with the cranium, almost in their natural positions ; 

 so that here we have not only proof respecting these scales, but the true 

 nature of the hatchet-shaped bones is also established. 



