46 Mr. T. Gill on the Affinities of 



the chin obtuse. Notwithstanding such characters, its affinity 

 to Lepidotus was evidently so great, the form, structure of the 

 fins, especially the anomalous form of the pectorals, and the 

 development of the opercular bones coinciding, that I felt com- 

 pelled to retain it in the same subfamily, in contradistinction 

 to one containing Trichiurus (= Lepturus, Art.) and Eupleuro- 

 grammus*. The colour arrested my attention, there being six 

 or seven narrow bands, the lateral line running through the 

 fourth ; the interval between the two dorsal bands was more 

 indistinct, and the two might readily be confounded ; the width 

 of the two would equal about a sixth of the height, while the 

 width of the single ones was contained about fifteen or sixteen 

 times in the height. The two lower bands were more indistinct. 

 I was therefore at once reminded of the Trichiurus lepturus of 

 Hoy ; and the similar development of the bars, as well as the 

 approximation in proportions, compel me to believe that Hoy's 

 second specimen is in reality a species of the genus Evoxy- 

 metopon, if not indeed identical with the Cuban fish itself (E. tce- 

 niatus, Poey). The greatest height of the latter, at the scapular 

 region, is contained scarcely more than twelve times (12J-) in 

 the extreme length, while a short distance behind, and for a 

 considerable distance, it is contained from thirteen and a half to 

 fourteen times. The head is contained eight times and a half, 

 and the caudal, at its longest rays, twenty-nine times and a half 

 in the same. The anus is midway between the snout and the root 

 of the caudal. In this last respect it disagrees with the specimen 

 signalized by Hoy, according to whom the anus was very con- 

 siderably within the limits of the first third of the length 

 (46:153 + %). Such a position is extremely improbable in a 

 representative of the subfamily of Lepidopodinse, to which the 

 specimen doubtless belongs. The true anus, on account of its 

 small size, was probably overlooked, and a rupture of the skin 

 mistaken for it. May we not hope that some British naturalist 

 will soon release us from our doubts, and verify the systematic 

 position of Hoy's fish ? 



3. Polyprosopus, Couch. 



Having provisionally adopted the generic name Polyprosopus, 

 proposed by Couch in the ' Analytical Synopsis of the Order of 

 Squali/ remarking at the same time that the genus was "not 

 yet well established," it seems advisable now to express my con- 



* Gill, " Synopsis of the Family of Lepturoids, and Description of a 

 Remarkable New Generic Type," in ' Proc. Ac. Nat. Sc. Philadelphia,' 

 1863, p. 224, &c. In this article I have suggested the relation of Hoy's 

 fish and Evoxymetopon ttfniatus. 



