No. 400.] ZONES IN ARIZONA AND NEW MEXICO. 293 
Tucson it produces Aspidiotus candidulus Ckll, Toumeyella mirab- 
is CklL, Eriococcus quercus toumeyi Ckl. and the Xerophilaspsis. 
The mesquite (Prosopis glandulosa) of the Mesilla Valley produces 
Icerya rileyi Ckll and Dactylopius prosopidis Ckl. The mesquite 
(Prosopis juliflora) of Jamaica produces Zcerya rose R. and H. and 
Dactylopius virgatus Ckll. 
* 
(4) Species of the Mesilla Valley absent from the Salt River Valley. 
A curious case is that of the mistletoe of the cottonwood, Phoradendron 
macrophyllum (Phoradendron flavescens var. macrophyllum Engelm., 
Bot. Wheeler Surv., p. 252) which is abundant and destructive on the 
Populus fremonti of the Mesilla Valley, but does not go up the valley 
of the Rio Grande as far as its host, or down into the Salt River Valley, 
where the same cottonwood abounds. Itis not that it is absent from the 
Gila basin, for it was first described from the Gila and Bonita Rivers. 
Its absence from the —— mee — is oe sé aopa 
McClatchie; and, indeed, 
The bag-worm (Oz£eticus NONAS of the Mesilla Valley, piee com- 
mon.at Tucson, was not observed in Salt River Valley. 
(5) Ants of Buckeye and the Mesilla Valley. 
A series of ants collected at Buckeye was kindly determined 
for me by Mr. Ernest André, and it appears that the ant-fauna 
of this region has little in common with that of the Mesilla 
Valley, as witness the accompanying lists : 
MESILLA VALLEY. 
Camponotus maculatus maccooki Pogonomyrmex barbatus Sm. (race 
Forel 
. fuscatus). 
C. marginatus decipiens Emery. P. badius Latr. 
Formica subsericea subpolita Mayr. P. californicus Buckl. 
Forelius maccooki Forel. Monomorium minutum Mayr. 
Lasius umbratus bicornis F oerst. M. pharaonis 
Dorymyrmex pyramicus Rog. Pheidole morrisi Forel. 
Aphenogaster albisetosa Mayr. Solenopsis geminata Fabr. 
A. cockerelli André. Cremastogaster leviuscula clara 
Tapinoma anale André. ayr. 
T. sessile Say. . Labidus harrisii (Hald.). 
Atta (Trachymyrmex) n. sp.? 
BUCKEYE. 
Atta versicolor Perg. Dorymyrmex pyramicus Rog. 
Cremastogaster atra Mayr. Prenolepis vividula guatemalensis 
_Aphenogaster pergandei Mayr. Forel. 
