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



bright red encircling the second and part of the preceding rings, will 

 readily separate this species from its allies. 



DESIDERATA. 



Trypoxylon carinatum, Say, Bost. Jour. 1ST. II. i. p. 374. (1837). 



"Indiana," (Say). 

 T. subimpressum. Smith, Cat. Hyra. Br. Mus. iv. p. 380. (1856). 



St Domingo, (Smith). 

 T. succinctum, Cress., Proc. iv. p. 149. (1865). 



Cuba. 



Subfamily MELLINlNiB. 



Mellinidce, Daklb., Hym. Eur. i. p. 226. (1843—45). 

 Mellinites, St. Farg., II. N. Ins. Hym. iii. p. 85. (1845). 



This subfamily, as we would consider it, is known by the cubical 

 head, very broad front, and slender antennae. The abdomen in the 

 typical genus is pedunculate, in Alyson, sessile. The enclosure of the 

 propodeum is very large, square and rugose, or scutellate and highly 

 polished. 



MELLINUS, Fabr. 

 Mcllinus, in part, Fabr., Ent. Syst. ii. 285. (1793). 



Head half as long as broad, the sides narrowing behind. Ocelli 

 placed modei'ately far apart, in a triangle a little below the vertex. 

 Eyes rather long and narrow, within somewhat concave, approximating 

 on the vertex. Front broad, square, somewhat convex in front, as 

 long as broad; it is flat, narrowing towards the front in % , while 

 in $ the sides are parallel. The base of the clypeus and foramina are 

 in a straight line, reaching from the lower angles of the eyes. The 

 epicranium is hardly raised between the bases of the antennas. The 

 middle region of the clypeus scarcely passes beyond this line, and is half 

 as long as broad. Mandibles in 9 bevelled on the outer third, 3-toothed, 

 the middle much the longer, the lateral ones indistinct, antennae rather 

 long, hardly thickened in the middle, 2d joint thick, half as long as 

 broad, somewhat flattened, 3d globose, remaining joints of very uni- 

 form length. Thorax oval, narrowing more rapidly than usual behind 

 the middle. Pro-scutellum rather narrow, thickened and rounded 

 above ; meso-scutum hardly as long as broad, square. Both the scu- 

 telluui and meta-scutellum longer than usual. Enclosure of the pro- 

 podeum forming a large shield-like piece, with a distinct suture, either 

 smooth or with an oval ridge upon its surface ; from its hind margin it 

 is suddenly bent down ; middle flanks much enlarged, full, convex and 

 horizontal ; third flank more inclined, apparently laying on the top of 

 the middle ones, and produced beyond. Middle trochanters as long 



