42 2 Bulletin American Museum of Natural History. [Vol. XIX, 



appears to be an expansion of an intemeural bone. This has 

 probably formed a support for the scute. The first inter- 

 neural support of the dorsal fin is similarly expanded. Along 

 the position of the lateral line is seen a succession of small 

 thin scutes, each not more than 2 mm. long. These are to be 

 observed as far backward as the rear of the dorsal fin, where 

 they lie close to the upper border of the vertebrae. It is 

 probable that they continue to the base of the caudal. I 

 have observed no traces of the hooked dermal scutes that are 

 described as occurring at the base of the tail of some species. 



The pectoral fin has had a length of at least 25 mm., and it 

 must have had somewhat more than 15 rays. The ventrals 

 arise about 30 mm. behind the pectorals and slightly behind 

 the origin of the dorsal fin. Its rays are somewhat damaged 

 in both specimens, but they were at least 17 mm. long. The 

 number of dorsal fin rays cannot be accurately determined, 

 since some are wanting in both specimens; but there were 

 probably 16, as in £. longidens. The anal fin was supported 

 by 19 rays, so that the fin does not appear to have differed 

 from that of E. longidens. The caudal fin is deeply forked, 

 and some of the external rays are rather strongly developed. 



In the specimen showing the head there are 24 vertebrae in 

 front of the origin of the dorsal fin, and 15 behind this point; 

 therefore 39 altogether, possibly 40. Dr. A. S. Woodward, in 

 his description of Enchodus longidens (Cat. Foss. Fishes, IV, 

 p. 199), states that there are 24 vertebrae in the caudal region 

 of the latter species. In our specimens from Hakel, the 

 twenty-fourth vertebra from the base of the caudal fin will 

 be on a line joining the base of the ventral fins with the an- 

 terior portion of the dorsal. Not more than 19 or 20 verte- 

 brae can be fairly assigned to the caudal region. This may 

 furnish us with one difference between E. longidens and E. 

 marchesettii. Another will probably be found in the different 

 forms of the dorsal scutes, those of E. longidens being broadly 

 oval, those of our Hakel specimens elongated oval. 



Besides the specimens described above, there are in the 

 collection three others which probably belong to the same 

 species. One of these, No. 4527a (3735), is from Hakel; the 



