YUCCA MOTH AND YUCCA POLLINATION. 139 
on joints 8-11, but rather increasing in size; by the greater shortness 
of joint 11, and the greater length of joint 12; and by the apex not being 
so rounded, and not extending beyond the two broad anal processes, 
At maturity the maxillary pieces are somewhat flatter, owing, doubtless, 
to the fact that in Q the spiny cylindrical tentacles lie stretched nearly 
their whole length, and cause them to bulge more, 
Imaco (Pl. 34, Fig. 1, b, c).—Average expanse, 9 25 mm.; 
23 mm. Primaries, above, uniformly silvery white, the scales loosely set; 
fringes concolorous; beneath, pale fuscous, with a brassy reflect'on; 
paler internally; fringes either concolorous or paler; costa with a brush 
of dark hairs. Secondaries semi-transparent, pale fuscous both above 
and below; paler internally, the fringes white and the brush on shoulder 
dark. Head white; antenne and tongue dingy yellow; maxillary palpi 
of same color, with the exception of tentacle, which is darker; labial 
palpi with scales on second joint dark brown above; eyes black. Thorax 
white. Legs dingy yellow, more or less covered with pale scales. 
Abdomen with the terminal joint in 2 always bare, with the exception of 
a few short, stiff hairs near tip, and the scales on the other joints very 
loosely attached. 
Described from many specimens of both sexes. Remarkably uniform 
in characteristics, no other variation noticeable than in size. 
PRONUBA MACULATA Riley. 
[Pl. 42, Fig. 2.] 
The species was described (Proc. Am. Ass’n. Adv. Sci., 
Vol. XXIX., August, 1880), from two females and five 
males, taken by Mr. H. K. Morrison at Caliente, Kern Co., 
California, upon the flowers of a species of Yucca, unde- 
termined at that time. Since then I have taken it in the 
flowers of Yucca whipplei near San Diego, Cal., and Mr. 
A. Koebele has reared it from larve in the seed-pods of 
this same Yucca taken at Newhall, Los Angeles Co., Cali- 
fornia. 
In June, 1876, I received from the late Dr, C. C. Parry 
pods and flowers of this Yucca collected at San Bernardino, 
which showed evidence of Pronuba work. The pollen is 
abundant and quite glutinous, and the tentacles of the moth 
would seem to be fitted for dipping into and coiling around 
the same ; while the modification of the tongue plainly indi- 
cates that it isan accessory organ in this collecting and polli- 
nating, and adds strength to the suggestions already made 
(p. 110) that the tongue in this genus is not a sucking organ. 
The stamens in this Yucca are long and straight, the style 
short and constricted, and the stigma expanded and peltate. 
Of all the Yuccas it would seem to be most easily self-fer- 
