Vout. II, Pr. II] WHEELER—GALAPAGOS ISLANDS ANTS 291 
The specimen from which Smith drew his description was 
evidently a worker minor. 
C. planus belongs to a group of small Camponoti which 
Forel has recently segregated as the subgenus Myrmorhachis. 
It comprises several neotropical forms rather closely related 
to planus, notably quadrilaterus Mayr, rectangularis Emery, 
bidens Mayr, mucronatus Emery. So far as known the 
American species all nest in hollow twigs or in dead wood. 
30. Camponotus (Myrmorhachis) planus peregrinus Emery. 
Camponotus peregrinus Emery, Ann. Soc. Ent. France, 63, 
1393) py Ole: 
Camponotus (Myrmorhachis) peregrinus Forel, Rev. Sse 
Zool. 22, 1914, p. 274 %. 
As I have seen no specimens of planus from Chatham 
Island, I regard the form described by Emery as possibly of 
varietal rank, although it is by no means certain that his 
specimen, which was taken by Dr. George Baur on the vessel, 
came originally from the island. I translate Emery’s descrip- 
tion in its entirety, although it contains very little that does 
not agree with specimens of the typical planus. 
“Worker minor. Black, opaque, with the mouth, antenne 
and legs, excepting the coxz, ferruginous; pilose, with the 
head and thorax very sparsely pubescent, the gaster with 
dense griseozeneous, shining, silky pubescence. Head sub- 
rectangular, clypeus in front broadly rounded, obtusely car- 
inate, mandibles short, 4-toothed, eyes at the posterior part 
of the head. Thorax with distinct sutures, dorsally depressed, 
sides obtusely marginate, epinotum behind abruptly truncate 
and obsoletely bituberculate, its declivity concave, somewhat 
shining. Petiole truncate behind. Head and thorax very 
densely, petiole more sparsely punctate; gastric segments 
transversely rugulose-punctate; mandibles, scapes and legs 
delicately punctate; legs without erect hairs. Length 4.3 mm. 
“This species belongs to an exclusively American group, 
and among the species known to me in nature, it approaches 
most closely C. guadrilaterus Mayr, from which, however, it 
differs considerably. The head is a little longer than broad 
if it be regarded as truncated in front at a level with the 
