156 HYMEXOPTERA. 



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. leucomelas ; the cell was a little shorter 

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

 the Odynerus Avas 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 

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

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

 and that a blind adherence to fixed mechanical laws does not 

 obtain in these insects. 



Tiie larvjB of Odynerus and Eumenes are carnivorous. 1 

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

 deserted nest of a Clisiocampa^ which were stored with micro- 

 lepidopterous larvai and pupa?, still alive, having been ])ara- 

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

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

 as long as broad ; the rings of the body are moderately 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 Odynerus ; the second subcostal 

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

 triangular. The genus is easil}' 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 



* EXPLANATIOX OF PLATE 5. Fig- 1- Mouth of the tunnel of Aiigorlilorn pnrus ; 

 from Emerton. Fig. 2. Cells of O^mla pncificn ; coninnmic;ited by Mr, Sanborn. 

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

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

 Ustes aunidnrin • from Saussure. Fig. 5. Three primitive cells of Polistes; na, top 

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

 6(7, a coll farther advanced, consisting of iour cells, each containing an c^g, and 

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

 Fig. 7. Cells of /cflj-ja gnttatipennis, showing that each cell is l)uiltup independently 

 in regular hexagons. Fig. S. Ground plan of a similar nest. Fig. 9. Ground plan 

 of cells of Tdtua morio ; from Smith. Fig. 10. Nest of Mischocyttnnt>< hihiatus : 

 from Saussure. Fig. 11. Nest of Apu'icn pallida; from Saussure. Fig. 12 Nest of 

 Odynerus birenimnculatus. Fig. 1.3. Nest of Odi/nerua alhophaleratns ; origiu&I, 

 Fig. 14. Mud cell of Pelopmus Jtuvipea ; original. Fig. Li. A row of spherical cell» 

 of E 11171671 es fraterna, with the female; from Harris. 



