ANTS VS. COTTON-WORMS, 



187 



Genus IRIDOMYRMEX, Mayr. 



Verhdl. d. k. k. zool.-bot. Ges. in Wien, Bd. xii, 1862, Z. 702. 



The workers vary very little, and only in size. The worker and the male are of the 

 same size ; the female is much larger. The maxillary palps have 6 joints, the labial 

 palps 4 joints. The clypeus is a little prolonged between the insertions of the an- 

 tennae. The clypeal fosse is joined with the antennal fosse. The frontal area is 

 triangular, indistinct. The scale of the petiole 

 is vertical, unarmed. The sculpture of the 

 body is very fine ; the chitinous skin is elastic 

 and not brittle, as is the case for the most 

 part in other ants; all the spurs are pecti- 

 nated. 



No. 3. I. McCooki, FOREL, in lift. 



This ant is a small yellow ant, about three 

 thirty-seconds of an inch in length. Dr. Forel 

 refers to it in his Etudes Myrmtcologiques for 

 1878, p. 382, and reference is also made to it 

 in my Agricultural Ant of Texas, pp. 202-3, 302. 

 I found numbers of this species traveling in 

 long lines across or near to the nest of the 

 agricultural ant. Usually their route was es- 

 tablished upon blades of grass growing on the 

 nests or along low tufts of grass on the mar- 

 gin. They traveled in single, or " Indian " file, 

 one behind the other. They appear to be on 

 friendly terms with their large neighbors. 

 The specimens sent me in alcohol were taken 

 in the act-of attacking the cotton- worm. 



Subfamily MYRMICIDAE, SMITH. 



Ants having a sting, except with the males. 

 Two nodes or joints upon the petiole. The 

 nymphs always naked. 



Catalogue Brit. Hymenoptera, 1851. 



Genus CREMATOGASTER, Lund. 



The second joint of the petiole articulates 



upon the superior face of the first segment of FIG. 36. Crematogaster lineolata. 

 the abdomen. Abdomen is cordiform, flat- 

 tened above, rounded below, and pointed at the extremity. The maxillary palps 

 have 5, the labial palps 3 joints. The antennae have 11 joints. The metanotum is 

 furnished with two spines. 



No. 4. C. lineolata, Say. 



1836. Myrmica lineolata, Say, Boston Journal Nat. Hist., voL i, p. 290. 



I860. Oecodoma (Atta) arborea, Buckley, Trans. Am. Ento. Soc. Phil., p. 349. 



18G6. Crematogaster lineolata, Mayr, Verb, zool.-bot. Ges. in "Wien, xvi, p. 901. 



Worker major. Length, & inch (Figs. 4, 5, 6). 

 Worker minor. Length, i inch. 



