54 
ZOOLOGICAL GEOGRAPHY. 
[part lit. 
(Cuculidae) ; Monasa (Bucconidse) ; many genera of Trochilidse ; 
and Nothocercus (Tinamidse) ; none of wliicli extend further 
north. A considerable number of the peculiar genera noted 
above, are also found in this restricted area, which is probably 
one of the richest ornithological districts on the globe. 
Reptiles. — These are much less known than the preceding 
classes, hut they afford several peculiar and interesting forms. 
Snakes are perhaps the least remarkable ; yet there are recorded 
4 peculiar genera of Calamariidae, 1 of Colubridee, 1 of Homalop- 
sidm, 3 of Dipsadidee ; while Boa and Flaps are in common with 
South America. Lizards are much more specially developed. 
Chirotes, one of the Amphisbaenians, is confined to Mexico and the 
southern part of the Nearctic region ; Heloderma forming a pecu- 
liar family, Helodermidae, is Mexican only ; Abwnia and Barissia 
(Zonuridae) are also Mexican, as is Siderolampus belonging to 
the Scincidse, while Blepharaetitis (same family) inhabits Nicara- 
gua ; Brachydactylus, one of the geckoes, is from Costa Rica ; 
while Phymatolepis, Bamanctus, Corytheolus, Cachrix , Corytho- 
phanes and Chamoeleopsis, all belonging to the Iguanidae, are con- 
fined to various parts of the sub-region. In the same family we 
have also the Antillean, Cyclura, and the Nearctic Phrynosoma and 
Tropidolepis , as well as the wide-spread American genus Anolius. 
Among the tortoises, Staurotypus, allied to Chelydra, is found 
in Mexico and Guatemala ; and another genus, Claudius, has been 
lately described from Mexico. 
Amphibia. — These are chiefly Batrachians ; Rhinophryna 
(forming a peculiar family) being confined to Mexico ; Triprion, 
a genus of Hylidse, inhabiting Yucatan, with Leyla and Stra- 
bomantis (Polypedatidse) found only in Costa Rica and Yeragua, 
are peculiar genera. The Salamandridae, so abundant in the 
Nearctic region, are represented by a few species of Amhlystoma, 
and Spelerpes. 
Fresh-water Since the British Museum catalogue was 
published, a valuable paper by I)r. Gunther, in the Transactions 
of the Zoological Society for 1868, furnishes much additional 
information on the fishes of Central America. In that part of 
the region south of Mexico, 106 species of fresh-water fishes are 
