30 Psyche [March I, 
An interesting mermithergate of stercorarius was sent 
me, with a portion of the colony in which it was living, by 
Dr. Wolfgang von Hagen, who took it during September, 
1932, in the state of Guerrero, Mexico. It differs from the 
mermithergates of consobrinus and piper (dus in being more 
clearly a modified maxima with some of the characters of 
the female. Though smaller and narrower, the head com- 
bines the characters of these two castes as shown by its 
sculpture, the shape of the antennae, mandibles, clypeus, 
frontal carinae, etc. The normal maxima measures 12-13 
mm., its petiole and gaster 4-4.5 mm., its head, including 
the mandibles 4.6 x 3.5 mm. The normal female is 14-15 
mm. long, the gaster and petiole 6.5 mm., the head 3.5 x 3 
mm. The corresponding measurements of the mermither- 
gate are: total length (in alcohol) 15 mm.; gaster and 
petiole 7 mm.; head 3.5 x 2.5 mm. Its head is decidely 
longer than broad, nearly as broad in front as behind, with 
rather straight subparallel sides, the posterior border less 
concave than in the maxima, the posterior corners rectan- 
gular as in the female, but with a distinct transverse im- 
pression on each side just behind the eye. This impression 
is absent in all the normal female castes. Eyes larger, 
more convex and situated more laterally when the head is 
viewed from above than in the maxima and therefore more 
like those of the female. There are no traces of ocelli. 
Mandibles convex like those of the maxima, with coarse 
teeth, but the terminal tooth is longer, as in the female. 
Antennal scapes stout and distinctly flattened distally as in 
the large media, maxima and female, extending half their 
length beyond the posterior border of the head (in the 
maxima less than %, in the female about %). Clypeus 
shaped as in the maxima, carinate, but with the anterior 
lobe shorter though angularly excised in the middle and 
strongly toothed at each lateral corner. Thorax also like 
that of the maxima, but smaller, shorter and somewhat 
more convex in the mesonotal region, with more sloping 
base to the epinotum. Metanotal sclerite very short as in 
the maxima but more distinct owing to the more pro- 
nounced mesoepinotal impression. Petiole decidedly larger 
and broader than in the maxima, its superior border dis- 
