286 University of California Publications in Zoology (Vou. 28 
Summarized, the foregoing gives: 
Species peculiar to California -........-.---------------------:-c--eeeesneeeeees ee ese 41 (23%) 
Species which on the west coast of North America are confined to 
CB BORMER WAC 52 ye 5 el eee cc ee ese senor n cece emcee ees cee oe ee ated eet ee eer 42 (23%) 
Species found in California and the region north of it -............-----.-- 101 (55%) 
Species found in California and the region south of it -..........--.------ 95 (52%) 
Species common to California and the regions both north and south 27 (15%) 
Species finding the northern limit of their range in the Bering Sea 9 ( 5%) 
Species finding the northern limit of their range in the Aleutian- 
Southeastern Alaska stretch 22622 noe cece cece ceccenne cern cneennanenemnancnane 47 (27%) 
Species finding the northern limit of their range in the British 
@olumibis-Oreeon ystreteh ice aaa aes ccc anne ease meen seen 40 (22%) 
Species finding the southern limit of their range in the Coronados- 
Magdalena Bay stretch -_..........-.--------------c-ce-s-ccceeeeeeceeeeeeeeceeeeneceeneseesece 41 (23%) 
Species finding the southern limit of their range in the Gulf of 
yeah eTefL0) Te7H01 A OO Tod FO YOO Ce ce ce cae ee 39 (21%) 
Species found at Panama or farther south -.........-.------------------------------ 12 ( 7%) 
Species occurring only in the stretch between the Aleutian Islands 
and Magdalena Bay -.2n.....---------c-------n--ne-ceceeeeeneeeeneonnecennnneneenennencenneene 133 (73%) 
Species also reported from the western north Pacific, chiefly from 
JF 0 30 ame ee Me Se CEP ee eee L7G Son 
Species also reported from the eastern littoral Atlantic -.......... 4 ( 2%) 
Cosmopolitan 1 012X112 eee Ran ee eee eo ene area 4 ( 2%) 
Pelagic Species © -.-.-.------2-----------cencencnoscceeecesceeencenensnonnnnsnenssenencanecnensnnensraannnnns 2 ( 1%) 
Species having a bathymetric range exceeding 500 fathoms -.......... 5 ( 3%) 
The California littoral decapod fauna is almost wholly confined 
to the west coast of North America; in fact, forty-one (23%) of the 
forms represented in it are peculiar to California waters alone. 
Exclusive of cosmopolitan and near cosmopolitan species only sixteen 
(9%) have been reported from the western North Pacific, chiefly 
from Japan, and only twelve (7%) from as far south as Panama or 
farther. If we consider Crangon dentipes, which occurs also in the 
Mediterranean and the Cape Verde Islands, as near cosmopolitan, 
only one non-cosmopolitan California species is common to the Atlan- 
tie littoral, viz., Epialtus bituberculatus. 
That nearly three-fourths (73%) of the species systematically 
treated in this paper, range, on the west coast of America, only within 
the stretch lying between the Aleutian Islands and Magdalena Bay 
seems indicative of the existence of a more or less uniform and con- 
tinuous faunal area of like extent,? within which these species are so 
2 North of California there are (based on Rathbun, 1904a, pp. 6, 7, and accom- 
panying table) but seventy-seven species occurring within the 100 fathom line 
which have not been reported from California. Of these twenty (26%) do not 
range north of the Aleutians, being confined to the stretch lying between those 
islands and the coast of Oregon; fifty-seven (74%), however, find their northern 
limits either in the waters of Arctic Alaska or the Bering Sea. But of the latter 
