190 HYMENOPTERA. 



that they often carry their subterranean roads for several hun- 

 dred yards in grassy districts, where the grass would prove an 

 impediment to their progress. On one occasion, to secure ac- 

 cess to a gentleman's garden, where they were cutting the 

 vegetables to pieces, they tunnelled beneath a creek, which was 

 at that place fifteen or twenty feet deep, and from bank to bank 

 about thirty feet. He also observes that the smaller workers 

 which remain around the nest do not seem to join in cutting or 

 carrying the leaves, but are occupied with bringing out the 

 sand, and generall}- work in a lazy way, very differently from 

 the quick, active leaf-cutters. Also, that the pieces of leaves 

 are usually dried outside before being carried in, and that if 

 wet by a sudden shower are left to decay without. He also 

 thinks that their lives are dependent upon access to 

 water, and that they always choose places where it 

 is accessible by digging wells. In one case, a well 

 was dug by Mr. Pearson for his own use, and water 

 found at the depth of thirty feet. The ant-well 

 which he followed was twelve inches in diameter." 

 Fig. 121. (Norton, American Naturalist, vol. 2.) 

 The genus Cryptocerus is remarkable for its flattened head, 

 with the sides expanded into flattened marginal plates, con- 

 cealing, or partly hiding the eyes. C. multispinosus Norton 

 (Fig. 121) is the most common species about Cordova, Mexico, 

 where they live, according to Surnichrast, within the trunks of 

 trees. 



CIIRYSIDID^E Latreille. In this small group the thirteen- 

 jointed autennre are elbowed, the eyes, are oval and the ocelli 

 distinct. The maxillary palpi are five, aftd the labial palpi 

 three-jointed. There are about four hundred species known. 



These insects are very different from the ants in their oblong 

 compact form, their nearly sessile, oblong abdomen, having only 

 three to five rings visible, the remaining ones being drawn with- 

 in, forming a. long, large, jointed sting-like ovipositor, which 

 can be thrust out like a telescope. The abdomen beneath is 

 concave, and the insect can roll itself into a ball on being dis- 

 turbed. They are green or black. The sting has no poison- 

 bag, and in this respect, besides more fundamental characters, 



