1974] 
W erner — Primitive Meloidae 
153 
perceptibly smaller, 0.03-0.04 mm across and not as distinctly flat- 
bottomed. Punctures of elytra deep across base, shallower behind, 
ca. 0.03 mm across and 0.05 center to center, round-bottomed, closer 
to 0.04 mm across near base, evenly distributed. Pubescence of upper 
surface slightly curved, decumbent, ca. 0.07 mm long, fairly incon- 
spicuous because it is not at all flattened and is concolorous with 
cuticle. Antennae with moderately dense suberect setae ca. 0.05 mm 
long from segment 2 to apex, a few such setae on first. Punctures of 
underside of thorax more rugulose, fairly shallow, ca. 0.02-0.03 mm 
across; those on abdomen smaller and finer, mose distinct from each 
other, ca. 0.02 mm across and 0.03 center to center. 
Female. Known only from allotype, 4.6 mm long. Antennae gen- 
erally shorter and less slender, without the suberect setae of the male. 
Unfortunately, most of antennae lost after description. Measure- 
ments in 0.01 mm, base to apex: 55/20, 34/16, 44/15, 50/15, 49/1 5> 
46/15, 47/15, 42/15, 39/15, 32/15, 54/I5- Last segment with little 
indication of the change of thickness seen in the male. Eyes dis- 
tinctly smaller and noticeably narrower than in male. Maxillary 
palpi smaller, last segment 0.24 mm long, 0.29 in male holotype, 
which is slightly smaller. 
Holotype male, allotype female and 1 1 male paratypes, Big Bend 
Nfational] P[ark], TEX [AS], 1850', Boquillas, May 23, 1959, 
light; Howden & Becker; 3 male paratypes same but May 13. Holo- 
type, allotype, and 11 paratypes in Canadian National Collection, 3 
paratypes in collection of author. 
Discussion. If this beetle is really a member of the family Meloi- 
dae, it is probably one of the most primitive yet discovered. Of the 
features that Selander (1966) lists as common to all meloids, in- 
cluding Eleticinae, Thambospasta conforms in only three: head with 
a well-developed vertex and narrow neck; pronotum not bordered 
laterally [with exceptions in Nemognathinae] ; and female gonostyli 
one-segmented. It resembles Eleticinae but not the other subfamilies 
in that the cuticle is more heavily sclerotized; abdominal sternum III 
is excavated and margined to accommodate the hind coxae; the female 
has a distinct ovipositor; and in the following characteristics of the 
venation of the hind wings: vein 2A 2 present and joined to iA by a 
crossvein (also in Meloinae: Lyttini: Prolyttina) ; and 3A X con- 
nected to base of 3A (in Eleticinae except Spasticini: Protomeloina 
and in some non-eleticines, apud Selander). It is very similar to 
Eleticinae : Spasticini : Anthicoxenina in that the male gonostyli are 
fused dorsally at the base and have a median dorsal projection; this 
