264 
Psyche 
[Vol. 90 
Myopias chapmani new species 
(Figs. 10, 26) 
Diagnosis, worker: A modest-sized member of the tenuis goup; 
head large, nearly square, with sides almost straight and nearly 
parallel; posterior margin concave. Eyes small but distinctly facet- 
ted. Mandibles rather short and stout; antennal scapes distinctly 
overreaching posterior border of head. Trunk robust, with broad 
and deeply impressed metanotal groove; propodeal dorsum less 
than twice as long as mesonotum. Node of petiole higher and wider 
than long, convex above. Gaster distinctly constricted between first 
and second segments. Sculpture predominantly smooth and shining, 
with spaced, indistinct punctures, especially on head, but sides of 
propodeum obliquely costulate, subopaque; dorsal propodeal sur- 
face finely roughened in part, and bearing a few, coarse, indistinct 
grooves and punctures, as well as a weak impression just caudad of 
its midlength. Color light ferruginous red. 
Worker, holotype: TL 5.7, HL 1.12, HW 1.07 (Cl 96), ML 0.57 
(MI 51), MLO 0.87, SL 0.95 (SI 89), EL 0.1 1, WL 1.77, hind femur 
L 1.06, hind tibia L 1.00 mm. 
Worker paratypes (21 from type nest series) range downward 
from the size of the holotype to the smallest individual, which has 
TL 5.2, HL 1.03, HW 0.98 (Cl 95), ML 0.54 (MI 52), MLO 0.81, 
SL 0.86 (SI 88), EL 0. 1 1 , WL 1 .63, hind femur L 0.94, hind tibia L 
0.86 mm. 
Head massive, sides only feebly convex, widest at posterior edge 
of eyes and tapering almost imperceptibly to rather abruptly 
rounded posterior corners; posterior border moderately concave 
across its middle half. Eyes almost round, with about 17 or 18 
facets, each situated nearly twice its own diameter away from man- 
dibular insertion; an indistinct groove extends the dorsal (mesal) 
orbital groove forward onto clypeal wing. Median clypeal lobe 
slightly longer than wide (CLL 0.14, CLW 0.13 mm), widest near 
apex, its anterior margin convex and free corners rounded. Median 
frontal sulcus wide and deep, extending back to posterior third of 
HL. 
Antennal scapes slender, gently bowed, slightly incrassate apicad, 
overreaching the posterior border of the head by about the same as 
their apical width when held straight back in dorsal full-face view of 
head. Funiculus slender, but with an indistinctly 4-merous club; all 
