29^ SMITHSONIAN MISCELLANEOUS COLLECTIONS IvOL. 45 



111 1777 J. J. Scopoli accepted the name Umbra as a generic 

 designation and referred it to his second order (ordo 2.), distin- 

 guished by the subcylindrical body {corpore tereti ant teretinsculo). 

 He interposed it between the genera Esox and Alhxila on the one 

 hand and Cobitis and Anableps on the other. His diagnosis was 

 equally applicable to almost all Cyprinodonts and doubtless, if the 

 author had known such, he would* have referred them to the same 

 genus.^ As it was, having adopted the genus from Kramer, the 

 species described by Kramer was evidently the type. 



By all later authors the type was overlooked or referred to the 

 genus Cyprinodon and not till 1842 was it properly recognized. 

 Then the illustrious Johannes Miiller found that it was a very distinct 

 genus and related not to the Cyprinodonts but to the pikes with 

 which he associated it in the same family. A few years afterward 

 (1846) Valenciennes proposed to isolate it as the sole representative 

 of a peculiar family to which he only gave the name " Les Ombres 

 (Umbra)" in common with the genus. He thought it was most 

 nearly related to the Amias, from which it differed mainly in the 

 absence of the suborbital cuirass (cuirasse sous-orbitaire) and 

 the lingual bone ; the simple non-cellular air-bladder further dis- 

 tinguishes it. Consequently he believed it was the type of a distinct 

 family (le type d'une famille distincte) which he proceeded to define. 



No representatives were recognized from America until near the 

 close of the first half of the nineteenth century, and then several 

 observers at nearly the same time obtained and described specimens 

 from different localities. Jared Kirtland, in 1840, described one 

 form under the name Hydrargyra Jiuii from individuals obtained in 

 northern Ohio ; Zadock Thompson, in 1842, found the same species in 

 Lake Champlain, and, failing to recognize it as the same as Kirt- 

 land's, gave a new name — Hydrargyra fiisca — to it ; in the same year 

 (1842) James E. Dekay gave a new name {Hydrargyra atricauda) 

 to the fish first described by Thompson, and having obtained from 

 Rockland county. New York, small specimens of another species, 

 he gave to the latter the name Lciiciscus pygnicuiis. None of these 

 authors recognized the relations of the new forms ; they all, however, 

 appreciated the likeness to the Cyprinodonts which actually exists, 

 although the fishes really belong to a different family, while the 

 last (Dekay) committed in one case an incomprehensible blunder, 

 inasmuch as his Lciiciscus pygincciis had none of the essential char- 



^ 256 Vmbra, Kramer. Maxilla inferior longior. Denies in maxillis. Caput 

 et Abdomen Cyprini. Membrana Branch, oss. (6). Pinnce inermes (7). 

 Scopoli Introd. Hist. Nat., p. 450, 1777. 



