60 CONTENTS OF EACH VOLUME. 
8, Pisces: by C. 'T. Reaan. 
The Introductory remarks to this subject (published in 1908) are arranged by the 
author under five headings -—(1) Principal Faunal Works on the Fresh-water Fishes 
of Mexico and Central America; (2) Principal Collections described in this Work ; 
(3) Classification ; (4) Geographical Distribution, illustrated by two separate maps; 
(5) The Shore-Fishes of the Atlantic and Pacific Coasts of Mexico and Central 
America. The geographical distribution is discussed at length under the headings to 
the separate families, ten of which are represented in the region, that of the Cichlide, 
Percide, Characinide, Catostomine, and Cyprinine being illustrated by shaded maps in 
the text. The author considers that the Nearctic and Neotropical Regions are quite 
distinct, and to explain the distribution of fresh-water fishes he says that the volcanic 
chain of mountains which stretches across Mexico from Colima nearly to Vera Cruz 
may be taken as the boundary. The Nearctic Region he divides into three subregions, 
one of which, the “Lerma,” lies wholly within Mexican territory. The Neotropical 
Region is also divided into three subregions, the Central-American subregion again 
being separated into four “ provinces,” Balsas, Guatemalan, San Juan, and Isthmian ; 
the limits of these are shown on Map 2. 
Mr. Regan says that the Cichlide, which form a very large family of fresh-water 
fishes, is the dominant perciform group in Tropical America and Africa. In America 
the Cichlide extend from Texas to Argentina, and comprise about 150 species. Africa 
appears to be somewhat richer in both genera and species, whilst three representatives 
occur in India and Ceylon. A mapis given in the text to show this distribution. He 
states that the Mexican and Central American Cichlids must have originated in the 
Southern Continent. 
‘The Percide are fresh-water fish inhabiting Europe, Northern Asia, North America 
east of the Rocky Mountains, and Northern Mexico. Fossil Percide are found in 
the Eocene deposits of Wyoming. 
The distribution of the Characinide, also fresh-water fish, is equally interesting. 
They extend from Northern Mexico over all the South-American continent, except 
the extreme south, and are found also in Africa, but not in Madagascar. 
These two families and the Lepidosirenide support the theory that a land 
connection between South America and Africa may have persisted until the beginning 
of the Tertiary period. 
The Catostomine extend from Guatemala all over North America and into Eastern 
Asia. 
The Cyprinine are found from Canada southward to the Lerma Valley in Mexico 
and throughout Africa and Eurasia, except in the extreme north. ‘They abound 
in Borneo, but are absent from Celebes. 
Amongst the Shore-Fishes entering fresh water, eighteen Pacific coast species are 
specially noted as having a closely related representative on the Atlantic. 
