76 
Psyche 
[March-J une 
Ocymyrmex arnoldi Forel 
(Fig. 3) 
Length (through spiracles) about 5.9 mm. Aphaenogastriform 
(i.e., stout and rather elongate; diameter greatest at AIV and AV ; 
slightly constricted at AI ; thorax stout and arched ventrally, but 
not differentiated into a neck; posterior end broadly rounded, anus 
ventral). Prothorax narrowed rapidly to diameter of head. Head 
small. Anus with a prominent posterior lip. Leg and wing vestiges 
present. About six differentiated somites. Spiracles small, dimin- 
ishing slightly posteriorly. Entire integument spinulose, the spinules 
minute and in short transverse rows, the rows longer and closer 
together on the venter of the anterior somites. Body hairs abundant, 
uniformly distributed, all short (0.025-0.075 mm long), with stout 
shaft and frayed tip. Cranium subhexagonal ; mouth parts rather 
large. Antennae minute, each in a small pit bounded medially by a 
high rim, three sensilla each bearing a tall spinule. Head hairs few, 
short (0.019-0.038 mm long), slightly curved, with short-bifid tip. 
Labrum paraboloidal, with three small ventral projections; anterior 
surface with six minute hairs; ventral border with two small sensilla 
on each ventrolateral projection and two groups of two larger con- 
tiguous sensilla ; posterior surface with 16 sensilla and scattered min- 
ute spinules. Each mandible vollenhoviform, but with only one 
medial tooth (i.e., slender, rather long and nearly straight, apex form- 
ing a moderately long slender tooth which is slightly curved medially ; 
with a narrow medial blade, from the edge of which arises one in- 
conspicuous medial tooth). Each maxilla with the apex paraboloidal 
and with minute isolated spinules; each palp a narrow frustum with 
four apical and one lateral sensilla ; galea digitiform with two apical 
sensilla. Labium paraboloidal, with a few short rows of minute 
spinules; each palp a skewed peg with five sensilla; an isolated sensil- 
lum between each palp and the opening of the sericteries, the latter 
a transverse slit. Hypopharynx with minute spinules in short rows. 
(Material studied: three larvae and one semipupa from Rhodesia, 
courtesy of Dr. W. L. Brown.) 
Trire Tetramoriini 
Genus Tetramorium Mayr 
T etramorium caespitum (Linnaeus) 
Bruder and Gupta 1972 — Description p. 366; photographs of 
first, second and third instars and semipupa; drawings of mandibles 
and maxillae of first, second and third instars. Life cycle in incipient 
colony: egg 9-12 days, larva 8-14 days, semipupa 5 days, pupa 12-18 
