52 Dr. A. S. Packard, Jr's Revision of the 



front, I suspect that they are either obsolete or concealed by the clyi 

 peus and adjacent epicranial region in the other families. We see 

 these lobes which I take to be homologous in the Bombyces, almost re- 

 placing the mandibles in Samia (or exceeding them in size as in Actias, 

 or hidden under the clypeus in many lepidoptera, where they are at 

 least entirely separate from the clypeus and joined or adjacent to the 

 piece that carries the mandibles.) In Phi/unthus it is large, longer 

 than broad and full convex sub-hexagonal. In Pemphredon , it is best, 

 described as being like that of Crabro, but short, often hirsute, raised in 

 the middle, and lateral lobes triangular, narrowing towards the sider. 

 In Mellinus it is much shorter than broad and its base nearly alinge ! 

 with the foramina. In Gorytes, the clypeus is larger and more that 

 half as long as broad, and the lateral lobes do not appear, they ar 

 concealed beneath, and the foramina are obsolute, as in the Vespida?. 

 (This foramina hardly seems to me to be a " cephalic stigma" as 

 Dr. Clemens suggests, as it is only present when the sub-man dibular 

 process is distinct from the side of the clypeus and the pieces that hold 

 the eyes, as in Ccrceris, &c, and the Lepidoptera, where the slight de- 

 velopment of the mandibles gives greater scope for that of the process 

 that seems to support them.) 



The " epicrauium" then, is actually divided into two pieces, one car- 

 rying the eyes, the other the antennae, the tergal pieces of which is 

 like and equivalent to the clypeus (which may be the tergite 0/ 

 maxillar-ring,) and the labrum (which may be the notal pieces of the man- 

 dibulai-ring.) Approaching these central pieces and coming out from 

 the sides of the eyes, are two broad, short lobe-like pieces, generally 

 yellow colored, which are separated from the antennal pieces, on the 

 one side, and the sub-mandibular piece below. 



Thorax. There is great uniformity in the prothorax and the 

 notal pieces of the meso-thorax. The propodeum varies greatly 

 in the appearance of the enclosure, throwing aside the two sides 

 of the scutellum, as it breaks through it. On the scutum of the 

 meso-thorax of Cerceris, there are two parallel impressions, noto-lateral, 

 which appear so plainly in Vespidae. In Cerceris this enclosure 

 is triangular, and rugose longitudinally. In Philanthus this still pre- 

 serves its form, but the suture is very indistinct. In Pemphredon, &c, 

 this region is broad, flattened and horizontal, and the hinder halt' 

 is suddenly bent down, and the sides are bent down from the broad sides 

 of the propodeum ; while in Gorytes and Mellinus where the hinder halt' 

 is produced more than usual, and narrowed somewhat, the sides of the 



