156 HYMENOPTERA. 



We have received from Mr. Angus deserted cells of Cera- 

 tiua in a syringa stem, in which we detected a pupa of an 

 Odynerus, perhaps 0, lencomelas ; the cell was a little shorter 

 than that of the Ceratina it had occupied. The cocoon of 

 the Odynerus was of silk, and almost undistinguishable from 

 the old cocoon of Ceratina. The wasp had dispensed with the 

 necessity of making a mud cell. If future research shows that 

 either this or any other species makes a mud cell or not at 

 will, it shows the intelligence of these little "free-agents;" 

 unci that a blind adherence to fixed mechanical laws does not 

 •obtain in these insects. 



The larvae of Odynerus and Eumenes are carnivorous. I 

 found several cells of 0. albophaleratus, June 22d, in the 

 ■deserted nest of a CUsiocampa, which were stored with micro- 

 lepidopterous larvae and pupae, still alive, having been para- 

 lyzed by the sting of the wasp. The larvae of the wasp was 

 short and thick, being, when contracted, not more than twice 

 as long as broad ; the rings of the body are moderatel}' convex, 

 and the pleural region is faintly marked. Prof. A. E. Verrill 

 has discovered the cells of an Odynerus at New Haven, forming 

 a sandy mass (Plate 5, Fig. 12) attached to the stem of a 

 plant. 



In Eumenes the lingua is very long, being narrower and 

 more deeply divided than in Od3'nerus ; the second subcostal 

 space of the wings is long and narrow, while in Odynerus it is 

 triangular. The genus is easily recognized by the very long 

 pedicel of the abdomen. Eumenes fraterna Say constructs a 

 thin cell (Plate 5,* Fig. 15) of pellets of mud, and as large 



* Explanation of Plate 5. Fig. 1. Mouth of the tunnel of AugocMora purus ; 

 from Einerton. Fig. 2. Cells of Omnia pnciflcn ; communicated by Mr. Sanborn. 

 Fig. 3. Vertical section of nest of Vespa with a group of primitive cells surrounded 

 by one layer of paper, and part of another; from Saussure. Fig. 4. Nest of Po- 

 lisies annulnrix; from Saussure. Fig. 5. Three primitive cells of Polistes; Sw, top 

 view of the same, one being eggless. The sides adjoining are angular. Figs. 6 and 

 6n, a cell farther ndvanced, consisting of four cells, each containing an e^g, and 

 with the edges of the cells built up higher and more decidedly six-sided; original. 

 Fig. 7. CcUs of Tcdvid f/iittntipennis. showing that each cell is built up independently 

 in i-egul;\r hexagons. Fig. S. Ground plan of a similar nest. Fig.!). Ground plan 

 of cells of Tiitaa nwrio ; from Smitll. Fig. 10. Nest of Afischncijftdrus hihiatus ; 

 fiom .Saussure. Fig. 11. Nest nf Api.h'n pullida; from Saussure. Fig. 12, Nest of 

 Odynerus birenimaculatus. Fig. Vi. Nest of Odyneru.i albophaleratus ; original, 

 Fig. 14. Mud cell of Pelopceus flnvipes ; original. Fig. 1.5. A row of spherical celli 

 of Eumenes fraterna, \v\tU the i'emu.\e; from Harris. 



