NOTES ON ANTETJOCHI^IiERA AND RELATED GENERA 

 OF CHIM.EROID FISHES. 



By Barton A. Bean and Alfred C. Weed, 



Of the Division of Fishes, U. S. National Museum. 



In a paper by Mr. Shigeho Tanaka,*^ recently received, he proposes 

 Anteliochimsera as a new genus of Chimseroid fishes, based on a single 

 adult male which he describes as a new species, Anteliochimsera cJiseti- 

 rJiampJius. This specimen was taken at a depth of about 400 fathoms 

 and bears a considerable external resemblance to Rhinochimsera paci- 

 Jica, with which it was carefully compared, and from which it differs 

 in many characters mentioned in the description. The genus Harri- 

 otta is not referred to by the author, although the points in which his 

 proposed new genus differs from Bhlnochimsera are precisely those in 

 which Harriotta differs from Rhinochimsera. In Harriotta, if the den- 

 tal plates are viewed by simply parting the lips instead of separating 

 the jaws, the appearance is as described for Anteliochimsera, and the 

 lack of armature of the supracaudal fin'' is the same in both. There- 



« Descriptions of one new genus and ten new species of Japanese fishes. Journ. Col- 

 lege of Science, ImperialUniversity, Tokyo, Japan, vol.27, article 8, 1 plate, October 

 10, 1909. 



b A review of the literature reveals the fact that there is a wide diversity of opinion 

 as to the nomenclature of the two vertical fins that go to make up the functional tail 

 of a chimteroid. Some authors refer to them as third dorsal and anal, thus conveying 

 the impression that all fishes of this group entirely lack a caudal fin. Others refer to 

 the fins, respectively, as upper and lower caudal lobe, and thus apparently homologize 

 them with the two lobes of the tail of a shark. It seems to us that neither of these 

 views is in entire accord with the facts and that a proper interpretation would make 

 the ventral of the two fins the homologue of both lobes of a shark's tail and the dorsal 

 one not represented in the adult condition of most living fishes, although present 

 in the embryonic condition of many. Further, it does not seem to us that the mere 

 fact that these fins are not developed to the extreme end of the caudal filament, and, 

 presumably, of the notochord, should militate in any way against regarding them as 

 truly caudal fins, for in the larval gar {Lepidosteus) the notochord extends to a consid- 

 erable distance beyond the fin, which ultimately becomes the caudal fin of the adult. 

 For these reasons we prefer the names supracaudal and infracaudal fins for the dorsal 

 and ventral of these two, respectively, as indicating clearly not only their position, 

 but also their true homology. See Notes on the North American Ganoids, by Prof. 

 Burt G. Wilder in Proc. Amer. Ass. Adv. Sci., pt. 2, 1876, pp. 151-166; also, The 

 development of Lepidosteus, by A. Agassiz in Proc. Amer. Acad. Arts Sci., vol. 14, 

 1878 (1879), p. 65. 



Proceedings U. S. National Museum, Vol. 37— No. 1723. 



661 



