SINGULAR NESTS. 483 



priate to tlie creature, inasmuch as the generic title signifies a 

 builder, or the founder of a city, and the specific name signifies 

 intense blackness, and is given to the insect on account of its col- 

 or. In general shape the insect resembles other species of its 

 genus-, but is rather larger than the generality of its kin, and is 

 conspicuous for its deep black color. ■ ■ 



The method of nidification which this species adopts is very pe- 

 culiar. The cells are formed with beautiful regularity, but are ar- 

 ranged in a very curious fashion. They are placed with their 

 mouths downward, as is frequently the custom with the cells of 

 hymenoptera, but are not quite perpendicular, inclining alternate- 

 ly to either side. Each cell is set rather lower than its predeces- 

 sor, so that the general effect is very peculiar, and gives to the 

 cell group a character which renders it at once recognizable. 



The second nest which is represented in the same illustration 

 is scarcely so striking in appearance as the preceding, but is 

 equally interesting, and to many minds more so, because the 

 architect is at present unknown, and there is some little mystery 

 about the edifice. That it is the work of a Polistes is evident 

 enough from the character of the cells, but it is not made by any 

 of the numerous species whose nests are already in European col- 

 lections. 



The color of the combs is a rather sombre brown, so that at a. 

 little distance the whole group would easily escape notice, espe- 

 cially if it were buried in the depths of the forest, as is the case 

 with many similar nests. The cells are about the same size as 

 those of the curious day nest which has already been described, 

 but they are undefended by any covering, and exposed to the 

 weather. 



It has been suggested by some observers that the combs might 

 have been originally protected by an outer case, and that the case 

 itself has been lost. The formation of the branch, however, from 

 which the combs are hung, serves to militate against any such 

 theory, as the twigs project so far that they must have been en- 

 veloped by the covering if it ever existed, while upon them there 

 is no trace of any such material as that of which the nest is made. 

 The inference is, therefore, that they were never intended to be 

 protected by a cover, but that they were intentionally exposed to 

 the air, as is the case with the habitations of Polistes and several 

 allied insects, whose homes will shortly be described. 



