Insects 191 



ant, known by the sharp conical elevation on the posterior part 

 of the thorax above. They nest in open sandy places. Iri- 

 domyrmex analis Andre is a very minute yellowish ant, without 

 ocelli. It is common in the southern states, but extends as far 

 north as Boulder. It is related to the destructive Argentine ant, 

 but appears to be harmless. 



Our Formicidae are placed in several genera, some of them 

 of unusual interest. The dominant types are Formica, Campon- 

 otus and Lasius. The nests of the larger species of Formica, 

 commonly seen in the foothills and mountains, are usually covered 

 with small sticks and other vegetable debris. We have forty 

 species and varieties of Formica in Colorado, but some of them 

 are hard to distinguish. Camponotus usually nests in rotten logs, 

 and may be found everywhere in the mountains. They are often 

 very large ants, with workers of various sizes. The discoidal cell 

 in the middle of the anterior wing of Formica and Lasius is lacking 

 in Camponotus. The species of Lasius are small, and nest under 

 stones, where they keep domestic animals, mealy bugs and 

 aphids. The common species (L. americanus Emery) is brown, 

 but the subgenus or related genus Acanthomyops contains ants 

 which are of a beautiful reddish yellow color, like amber. This 

 group has only three joints (instead of six) in the maxillary palpi, 

 and so has strong claims to be regarded as a genus. We have one 

 species, Acanthomyops latipes Walsh, which has curiously modified 

 legs. I have taken it at Boulder. 



In the Garden of the Gods and some other localities one may 

 find curious long-legged ants which disappear down vertical tun- 

 nels in the ground. If these shafts are excavated, it is found 

 that they are connected with galleries or rooms, to the roofs of 

 which hang numerous globular objects. These objects on closer 

 inspection prove to be worker ants, their abdomens distended to 

 the size and form of a pea, and full of a honey-like substance. 

 They are called repletes, and we recognize the famous Honey 

 Ants, which McCook named Myrmecocystus horti-deorum. Myr- 

 mccocystus means the ant cyst, and horti, of the garden, deorum, 

 of the gods. These repletes are fed by the ordinary workers far 

 in excess of their needs, and are able to regurgitate the sweet 

 substance to supply the rest of the colony when necessary. Hence 

 they are living preserve-jars. The food given to the repletes is 



