Vor. II, Pr. IT] WHEELER—GALAPAGOS ISLANDS ANTS 293 
English author says nothing about the bronzy pubescence of 
the gaster and describes the petiole as having a different 
form.” 
The omission to which Emery refers was probably due to 
the age of the specimen described by Smith, since it was taken 
by Darwin on the voyage of the “Beagle”? and not described 
till 42 years later. Smith’s description of the petiolar node 
as “incrassate, narrow, the sides nearly parallel, rounded 
above’, is not so very inapplicable to specimens which un- 
doubtedly belong to the true planus. 
31. Camponotus (Myrmorhachis) planus isabelensis, 
new variety. 
Worker major. Length 6.5—7 mm. 
Somewhat larger than the typical planus, with the sides of 
the head decidedly more opaque and with larger, scattered 
punctures. The cheeks bear short, erect, blunt hairs. The 
hairs on the front, vertex and thoracic dorsum are more 
abundant, and those on the gaster are somewhat shorter, the 
pubescence on the legs, especially on the tibize, is distinctly 
longer and less appressed. 
Worker minor. Length 4—5.5 mm. 
Very similar to the worker major in sculpture, pilosity and 
pubescence. The base of the epinotum is more concave in 
profile and much more distinctly bidentate posteriorly than 
in the worker minor of the typical form, and the border of 
the petiole is distinctly more acute. 
Female. Length about 8 mm. 
Resembling the worker major and differing from the 
female of the typical planus in pilosity. The pubescence on 
the gaster is noticeably longer and denser and more as in the 
worker. The petiolar border is entire. 
Male. Length 5—5.5 mm. 
Indistinguishable from the male of the typical form. 
Described from eight major and three minor workers taken 
by Dr. Williams in 1905 on Cowley Mt., South Albemarle, and 
16 major workers, 13 minor workers, five females and 27 males 
taken by the “Albatross” in 1899 (U. S. Nat. Mus.) on the 
same island. 
