108 THE NORTH AMERICAN SPECIES OF DROSOPHILA. 
XII. GEOGRAPHICAL DISTRIBUTION. 
Table 9 shows the number of species of each genus of the Dro- 
sophiline known from each of the main geographical regions. The 
Polynesian region is considered separately, because the data now 
available indicate that for this subfamily the fauna is more distinct 
from that of the rest of the world than is the fauna of any other region. 
This fact is probably due in large part to the incompleteness of the 
data, for the word ‘ Polynesian”’ in this case means practically “‘ Hawai- 
ian Islands.’’ The parts of the Oriental region nearest to these islands 
have not been well explored. Australia and New Zealand have been 
included in the Oriental region, again perhaps only because of a lack 
of data. These islands are practically unknown, so far as their 
drosophiline fauna is concerned. The same situation is found with 
respect to the relation of Madagascar to the Ethiopian region. 
Table 9 indicates that the Nearctic region is the poorest of all in the 
number of species that it contains. The actual number recorded from 
the Ethiopian region is somewhat less than that from the Nearctie, 
but Africa has been very much less thoroughly collected than has the 
Nearctic region. A discussion of each region in some detail follows 
the table. 
TaBLE 9.—Number of species of each genus in each region. 














Genus. Nearct.| Neotr. | Pale. | Ethiop.| Orient.| Poly. | Total. 
INCISEOREMUS reese eee eee ers eee eal heya eetees aise, Astaire aan ES 2 1 
PAT SITIO GE iis GPL ett eter Mace SS le apes if nie Rien HL Vedat eaten a A Ween (hd 3 
IMUIACIZASLEEM wae ine ee ok ia 1 1 0 erat ph We Te aL a Ske eee 1 
Blpsochstophorai coe cies eee ciallee asin 1 NS Be ae eal shag a lo aah 1 
(Chri ramh Lisi hana ote ets Pepi aN Le eT eG | cnt | ha 2 1 As el Rute 7 
Chymomiyzay. ain. Sats eas sna e + 2 5 LE OA Rasen [isimtotet cee MaeL 
Wlad och setae eo ik cs there ete ici sealet udwoks Wile akan ca IN 2, tone alll gee BT 1 
urtono tum ie restos ec ae 1 11 1 2 1 RNG Le 16 
IDE ETO PSOMIV AR Mpa oteieiel atrerelie oe] io cuit ot coen | haverers ceca a he kctape ts 1h aol hates oh He te ae Rey: 1 
Drosophila skye 150 hs eran 28 41 43 22 51 44 203 
GEO a Arche rine ere ene fais ules a leila stapeion PA NA Pa He 1 1 3 
MAIO MIVA S eo la etre le eleven eemeec| hth aicee ON Poece cap are lalUaeetome eit heise HSRG) Mee cee 6 6 
eucophongar nen) xed Lak le 2 Oise at 2018 seinen 45 
Mycodrosophila........... Gris 1 3 es 3 1 GEA Rea ee Os fe 9 
Pseudiastatace we sie cee cians 1 b VSR SUM cetera ecgeueas elie bao ae tal eal cP (ar 1 
Pseudophortica............ hes i a Bt A Ufo ta APRS Mas TS YO AR aur i 
Scaptomyza)y awit eee Bangin 3 2 VON eet 3, sie Se 15 
Sinophthalmus............ ety 2 are | Deemer NAB ite Wiss a, cee Specs | 1 
Medd ayeds eV SIR Gh iver CNH Nea ate nie Ree 2 5 9 1 a aes ae 28 
PDA GERM OCHS EA Actors sia Meno ces epee ibe decer ge fa eat Gen ded St rec bree | eh si ote ep ran ee 1 31 
DEPTIOUUSE ek ae eisai TVR rec nA 1 GO SEM ia Rt 1 j Ma Romesh 2 3 
ZY SOMFICN cate es aca iy eal Siecle ANC ROR Ya j eeeal ih ae. 8 3 
PRG Galera Apr ee ery a ia 45 81 78 43 97 52 360 


NEARCTIC REGION. 
This region is characterized by the presence of the two endemic 
genera Pseudophortica and Sinophthalmus. It has a relatively large 
number of species that also occur in other regions. The five cos- 
