582 DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 
fauna species which may be eapected to belong to it, although they are not yet disco- 
vered within its limits, I have excluded all species not actually known from Guatemala, 
although they have been obtained north and south of it. A collection made by Mr. 
Godman at Belize was of great value in determining this part of the fauna. 
Numerous species of fishes have been described trom Mexico'; and if we were better 
acquainted with their geographical distribution, it would have been useful to treat at 
least of the southern portion of them, in conjunction with the Guatemalan species. 
Unfortunately but a small proportion of the exact localities are known, so that at 
present no line can be drawn to indicate where the preponderance of nearctic types 
oyer tropical ones terminates. Thus, confining myself to the fishes occurring between 
the political boundary of Guatemala in the north and the Isthmus of Darien in the 
south, I would repeat that, previously to the receipt of the collections forming the basis 
to this Memoir, only a small number had been described, as will be seen from the 
following remarks :— 
§ 4. Historical account of Publications previous to this Memoir. 
It would be of but little advantage to enumerate the few isolated species incidentally 
described in general works or memoirs as occurring in Guatemala or Panama. How- 
ever, I must mention that the first traveller who collected fishes in these states appears 
to have been Baron von FrimpricustHat. I am not aware that any account of his 
travels has been published; but in a paper published by the late Jacop Hecken in 
‘Annalen des Wiener Museums,’ vol. ii. 1840, a single species is described, which is 
stated to be from Friedrichsthal’s Central-American Collection, and which I have 
recognized as belonging to the Lake-Peten fauna (Heros friedrichsthalii). The greater 
part of the collection made by this gentleman evidently remained unpublished until 
1864, when Dr. F. SreivpacuNer determined from it four other species (Denkschr. 
Akad. Wiss. Wien, xxiii.), viz.:—Heros urophthalmus (Gthr.), Heros triagramma=H. 
salvini (Gthr.), Heros melanopogon, and Petenia splendida (Gthr.). As we have received 
four of these species from Lake Peten, it is very probable that Baron Friedrichsthal 
visited and collected in that locality. 
In the second place I have to mention Dr. SEEMANN, who, as naturalist attached to 
the expedition of the ‘Herald,’ brought to England a collection of Central-American 
fishes. ‘These, as I have mentioned above, were originally deposited in the collection of 
Haslar Hospital, but no record as regards the origin of the specimens was kept, so 
that most of them are lost for the purposes of this Memoir. i 
In the year 1861 I received the first collections from Mr. Satvin and Capt. Dow. 
The species belonging to the families treated of in the 5rd volume of the ‘ Catalogue of 
Fishes’ were described therein; and a separate account of those sent by the latter 
' Prof. Troschel enumerates some 130 freshwater and marine species in Miiller’s ‘ Reisen in den Vereinigten 
Staaten,’ &e, 
