Vot. II, Pr. IT] WHEELER—GALAPAGOS ISLANDS ANTS 295 
and the ridge between the base and declivity is semicircular 
and entire, without indications of teeth. 
Worker minor. Length 4.5—5 mm. 
Like the worker major, but the epinotum is slightly con- 
cave in profile just in front of the ridge between the base 
and declivity. This ridge is very narrow and _ indistinctly 
bidentate. 
Female. Length 10 mm., wings nearly 11 mm. 
Larger than the female of the typical planus and var. 1sa- 
belensis and of a deeper black color, the thorax being without 
red markings. The pubescence on the gaster as in the type. 
Male. Length 5—6 mm. 
Like the male of the typical planus, except that the body 
and appendages are somewhat darker and more blackish. 
Described from five major workers, 11 minor workers, seven 
females and five males taken during November, 1905. by Dr. 
Williams from a single colony on Indefatigable Island. Al- 
though this form occurs on the same island as the preceding it is 
nevertheless so different that I am compelled to regard it as 
a distinct variety. 
Cotypes, 15 specimens, No. 457, Museum California Acad- 
emy of Sciences, and 15 in author’s collection and 8 in the 
Museum of Comparative Zoology. 
34. Camponotus (Myrmorhachis) planus fidelis, 
new variety. 
Worker major. Length 5.5—6 mm. 
Resembling the var. indefessus in stature, in the size of the 
head, pilosity and sculpture, but the pubescence of the head 
and thorax is much shorter and less conspicuous. On the 
gaster it is dense and rather long and has a pronounced sil- 
very lustre. The epinotum differs, however, from that of all 
the preceding varieties, the base being scarcely longer than 
the declivity and perfectly straight and horizontal in profile. 
The ridge separating it from the declivity is straight, trans- 
verse, rather blunt and entire, without any indications of 
teeth. The reddish color of the anterior part of the head is 
suffused with the black even on the vertex and occiput and 
