- PREFACE. 
them. The extent of the dispersion of each named form has, how- 
ever, been given so far as our present knowledge permits. 
In the Synopsis and its Supplement 997 species and subspecies 
were enumerated, and of these 789 were restricted to the regions 
north of the boundary of Mexico, leaving 208 that were found on 
both sides of the line. Of genera there were 120 of which only 42 
were not represented in Mexico. In the present work the species 
and subspecies number 1,018, of which 809 are restricted to Mexico 
and the countries and islands embraced in the volume, leaving 209 
also to be met with in the United States. The genera number 178, 
of which 78 are found north of the line, leaving roo peculiar to the 
Southern lands, the major portion of the excess over the northern 
genera being found in the Chiroptera. The Land Mammals in the 
Synopsis numbered 933, and the Sea Mammals 63; in the present 
volume the Land Mammals number 989 and the Sea Mammals 29, 
and but two of the latter are not found in northern waters so far 
as known, Megaptera n. bellicosa and Prodelphinus longirostris, 
although the first named probably does go into the northern portions 
of the Gulf of Mexico. 
The following table exhibits the genera that are represented on 
both sides of the northern boundary of Mexico, with their species and 
subspecies, showing the number of those that are restricted to each 
region, and also how many are common to both: 
Number of Number of Number of 
Species and Sub- | Species and Sub- | Species and Sub- 
species North of species South of species Common 
Mexican Line exican Line to Both Regions 
FTG OCA Tee Wiae wierd ota ee 1 aN 1? 
Joni 1) Ao) (Ae 6 Sie ae Mere meat ae 2 3 2 
SALTO PLEHAe e Wel) su rcaein chee 8 3 3 
Bassaniseusheera: = sucemin tote us 4 6 2 
Jeqehek als), cists Sines ener eee 7 16 I 
CIEL) Lee ne a me cue a 9 11* 3 
ASTOR on tees coer ak on art 4 I I 
CATCHING: os Areas + 2a ee tates 57 21 Il 
(CG fens), v5 a Seen Sa Be I I I 
GOnEDAtUSs terinrocielc ee ieeene ke I 8 2 
GOryiOrnintIS 5s ers nae 3 2 2 
(STIG SEOMUS yale nl kN ASI ieee I 8 I 
WY MOMMY Sine agrat cn ne eee 4 4 3 
DWaSyDteGUS: .).\.40. cee ae es I 2 I 
ND YS oni ah DSR Sow eden ckenrecs ciqcerth crock: I I I 
ONGEI DEUS! mo cscvctaeistaceote Cre 4 ) 2 
WOTPOCOMUy Shs. hie lisesi eee 14 13 6 
SRE UMI COM wheels vocal ss ae 5 I I 
NG LIG eS ceo o Pichaitec ares oe CLO aR 19 24 8 
SEIT eotorseniny aris seh ets set soca hae SU 8 I I 
CHROULYS ie catia is wp ieicrciohe Sie oes 15 I I 
Globicennalusi «fects ee ait 3 3 3 
PLOtETOMYS 5. i I 35 fe) 
MASI US ey neers te icinicts me ere 4 5 3 
