36 Psyche [April 



Description of Plate 4. 



Lycosa pikei, male 1, la, female lb, Ic. 



Lycosa nidifex, male 2, 2a, female 2b, 2c. 



Lycosa mis sour iensis, male 3, 3a, female 3b, 3c. 



Lycosa wrigJitii, male 4, 4a, female 4b, 4c, old female with cocoon of eggs, 4d. 



THE STANFORD EXPEDITION TO BRAZIL, 1911. 



J. C. Branner, Chief. 



PARABIOSIS IN BRAZILIAN ANTS.^ 

 By William M. Mann. 



During the different visits of the members of the Stanford Expe- 

 dition at Para, the suburb Souza was found to be the best collect- 

 ing ground, and much of their time was spent there. The com- 

 bination of forest and good trails, quickly reached by electric cars, 

 made the locality quite ideal for collectors having only a limited 

 time at their disposal. 



Here, as elsewhere in Brazil, ants abounded, and of these the 

 small, black Dolichoderus hispinosus Oliv. was most in evidence. 

 This species lives in carton nests, built on the branches of trees, 

 though often a colony is found in a deserted termitarium. After 

 a couple of attempts I gave up investigating the larger nests, for 

 when these were disturbed myriads of ants swarmed out, literally 

 tumbling over one another to the ground, where they scattered 

 in all directions in search of the disturber. On hurriedly leaving 

 the vicinity of one nest, I happened to leave my net lying on the 

 ground. On my return, a few minutes later, it was covered with 

 ants, each gripping so tightly that when I pulled it away its head 

 often remained attached to the net. In young trees along the 

 trails there were numerous small nests, four or five inches in diam- 

 eter, and several of these were opened. Each contained, besides 

 the Dolichoderus, a colony of a small black Cremastog aster. The 

 smaller ants were not scattered throughout the nest, but were 

 grouped in certain of the chambers. 



ForeP has recorded observations which he made in Columbia 



1 Contributions from the Entomological Laboratory of the Bussey Institution, Harvard 

 University, No. 54. 



sLa Parabioae chez les Fourmis. Bull. Soc. Vaud. So. Nat. XXXIV, 130, p. 380-385. 



